/*
$Id$

Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.

Redistribution and use of this software and associated documentation
("Software"), with or without modification, are permitted provided
that the following conditions are met:

1. Redistributions of source code must retain copyright
   statements and notices.  Redistributions must also contain a
   copy of this document.

2. Redistributions in binary form must reproduce the
   above copyright notice, this list of conditions and the
   following disclaimer in the documentation and/or other
   materials provided with the distribution.

3. The name "groovy" must not be used to endorse or promote
   products derived from this Software without prior written
   permission of The Codehaus.  For written permission,
   please contact info@codehaus.org.

4. Products derived from this Software may not be called "groovy"
   nor may "groovy" appear in their names without prior written
   permission of The Codehaus. "groovy" is a registered
   trademark of The Codehaus.

5. Due credit should be given to The Codehaus -
   http://groovy.codehaus.org/

THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
OF THE POSSIBILITY OF SUCH DAMAGE.

*/
package groovy.lang;

import java.beans.BeanInfo;
import java.beans.EventSetDescriptor;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.logging.Level;

import org.codehaus.groovy.GroovyBugError;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.classgen.BytecodeHelper;
import org.codehaus.groovy.control.CompilationUnit;
import org.codehaus.groovy.control.Phases;
import org.codehaus.groovy.runtime.CurriedClosure;
import org.codehaus.groovy.runtime.DefaultGroovyMethods;
import org.codehaus.groovy.runtime.DefaultMethodKey;
import org.codehaus.groovy.runtime.GroovyCategorySupport;
import org.codehaus.groovy.runtime.InvokerHelper;
import org.codehaus.groovy.runtime.MetaClassHelper;
import org.codehaus.groovy.runtime.MethodClosure;
import org.codehaus.groovy.runtime.MethodKey;
import org.codehaus.groovy.runtime.NewInstanceMetaMethod;
import org.codehaus.groovy.runtime.NewStaticMetaMethod;
import org.codehaus.groovy.runtime.ReflectionMetaMethod;
import org.codehaus.groovy.runtime.Reflector;
import org.codehaus.groovy.runtime.TransformMetaMethod;
import org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation;
import org.codehaus.groovy.runtime.wrappers.Wrapper;
import org.objectweb.asm.ClassVisitor;

/**
* Allows methods to be dynamically added to existing classes at runtime
*
* @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
* @author Guillaume Laforge
* @author Jochen Theodorou
* @version $Revision$
* @see groovy.lang.MetaClass
*/
public class MetaClassImpl extends MetaClass {

   protected MetaClassRegistry registry;
   private ClassNode classNode;
   private Map classMethodIndex = new HashMap();
   private Map classMethodIndexForSuper;
   private Map classStaticMethodIndex = new HashMap();
   private Map classPropertyIndex = new HashMap();
   private Map classPropertyIndexForSuper = new HashMap();
   private Map staticPropertyIndex = new HashMap();
   private Map listeners = new HashMap();
   private Map methodCache = Collections.synchronizedMap(new HashMap());
   private Map staticMethodCache = Collections.synchronizedMap(new HashMap());
   private MetaMethod genericGetMethod;
   private MetaMethod genericSetMethod;
   private List constructors;
   private List allMethods = new ArrayList();
   private List interfaceMethods;
   private Reflector reflector;
   private boolean initialized;
   // we only need one of these that can be reused over and over.
   private MetaProperty arrayLengthProperty = new MetaArrayLengthProperty();
   private final static MetaMethod AMBIGOUS_LISTENER_METHOD = new MetaMethod(null,null,new Class[]{},null,0);
   private static final Object[] EMPTY_ARGUMENTS = {};
   private List newGroovyMethodsList = new LinkedList();
   
   public MetaClassImpl(MetaClassRegistry registry, final Class theClass) {
       super(theClass);
       this.registry = registry;

       constructors = (List) AccessController.doPrivileged(new  PrivilegedAction() {
               public Object run() {
                   return Arrays.asList (theClass.getDeclaredConstructors());
               }
           });
   }

   private void fillMethodIndex() {
       LinkedList superClasses = getSuperClasses();
       // let's add all the base class methods
       for (Iterator iter = superClasses.iterator(); iter.hasNext();) {
           Class c = (Class) iter.next();
           addMethods(c);
       }

       Set interfaces = new HashSet();
       makeInterfaceSet(theClass,interfaces); 

       inheritMethods(superClasses,classMethodIndex);
       inheritInterfaceMethods(interfaces);
       copyClassMethodIndexForSuper();
       
       connectMultimethods(superClasses);
       populateInterfaces(interfaces);
       removeMultimethodsOverloadedWithPrivateMethods();
       
       replaceWithMOPCalls();
   }
   
   private LinkedList getSuperClasses() {
       LinkedList superClasses = new LinkedList();
       for (Class c = theClass; c!= null; c = c.getSuperclass()) {
           superClasses.addFirst(c);
       }
       if (theClass.isArray() && theClass!=Object[].class && !theClass.getComponentType().isPrimitive()) {
           superClasses.addFirst(Object[].class);
       }
       return superClasses;
   }

   private void removeMultimethodsOverloadedWithPrivateMethods() {
       Map privates = new HashMap();
       MethodIndexAction mia = new MethodIndexAction() {
           public List methodNameAction(Class clazz, String methodName, List methods) {
              boolean hasPrivate=false;
              for (Iterator iter = methods.iterator(); iter.hasNext();) {
                  MetaMethod method = (MetaMethod) iter.next();
                  if (method.isPrivate() && clazz == method.getDeclaringClass()) {
                      hasPrivate = true;
                      break;
                  }
              }
              if (!hasPrivate) return null;
              // We have private methods for that name, so remove the
              // multimethods. That is the same as in our index for 
              // super, so just copy the list from there. It is not
              // possible to use a pointer here, because the methods
              // in the index for super are replaced later by MOP 
              // methods like super$5$foo              
              methods.clear();
              methods.addAll((Collection) ((Map) classMethodIndexForSuper.get(clazz)).get(methodName));
              return methods;
           }
           public boolean replaceMethodList() {return false;}
       };
       mia.iterate(classMethodIndex);
   }
   
   
   private void replaceWithMOPCalls() {
       // no MOP methods if not a child of GroovyObject
       if (!GroovyObject.class.isAssignableFrom(theClass)) return;
       
       final Map mainClassMethodIndex = (Map) classMethodIndex.get(theClass);
       class MOPIter extends MethodIndexAction {
           boolean useThis;
           public boolean skipClass(Class clazz) {
               return !useThis && clazz==theClass;
           }
           public void methodListAction(Class clazz, String methodName, MetaMethod method, List oldList, List newList) {
               String mopName = getMOPMethodName(method.getDeclaringClass(), methodName,useThis);
               List matches = (List) mainClassMethodIndex.get(mopName);
               if (matches==null) {
                   newList.add(method);
                   return;
               }
               matches = new ArrayList(matches);
               MetaMethod matchingMethod = removeMatchingMethod(matches,method);
               if (matchingMethod==null) {
                   newList.add(method);
                   return;
               } else {
                   newList.add(matchingMethod);
               }
           }
       }
       MOPIter iter = new MOPIter();
       
       // replace all calls for super with the correct MOP method
       iter.useThis = false;
       iter.iterate(classMethodIndexForSuper);
       // replace all calls for this with the correct MOP method
       iter.useThis = true;
       iter.iterate(classMethodIndex);
   }
   
   private String getMOPMethodName(Class declaringClass, String name, boolean useThis) {
       int distance = 0;
       for (;declaringClass!=null; declaringClass=declaringClass.getSuperclass()) {
           distance++;
       }
       return (useThis?"this":"super")+"$"+distance+"$"+name;
   }
   
   private void copyClassMethodIndexForSuper() {
       classMethodIndexForSuper = new HashMap(classMethodIndex.size());
       for (Iterator iter = classMethodIndex.entrySet().iterator(); iter.hasNext();) {
           Map.Entry cmiEntry = (Map.Entry) iter.next();
           Map methodIndex = (Map) cmiEntry.getValue();
           Map copy = new HashMap (methodIndex.size());
           for (Iterator iterator = methodIndex.entrySet().iterator(); iterator.hasNext();) {
               Map.Entry mEntry = (Map.Entry) iterator.next();
               copy.put(mEntry.getKey(), new ArrayList((List) mEntry.getValue()));
           }
           classMethodIndexForSuper.put(cmiEntry.getKey(),copy);
       } 
   }
   
   private void inheritInterfaceMethods(Set interfaces) {
       // add methods declared by DGM for interfaces
       List methods = registry.getInstanceMethods();
       for (Iterator iter = methods.iterator(); iter.hasNext();) {
           Method element = (Method) iter.next();
           Class dgmClass = element.getParameterTypes()[0]; 
           if (!interfaces.contains(dgmClass)) continue;
           NewInstanceMetaMethod method = new NewInstanceMetaMethod(createMetaMethod(element));
           if (! newGroovyMethodsList.contains(method)){
               newGroovyMethodsList.add(method);
           }
           Map methodIndex = (Map) classMethodIndex.get(theClass);
           List list = (List) methodIndex.get(method.getName());
           if (list == null) {
               list = new ArrayList();
               methodIndex.put(method.getName(), list);
               list.add(method);
           } else {
               addMethodToList(list,method);
           }
       }
       methods = registry.getStaticMethods();
       for (Iterator iter = methods.iterator(); iter.hasNext();) {
           Method element = (Method) iter.next();
           Class dgmClass = element.getParameterTypes()[0]; 
           if (!interfaces.contains(dgmClass)) continue;
           addNewStaticMethod(element);
       }
   }
   
   private void populateInterfaces(Set interfaces){
       Map currentIndex = (Map) classMethodIndex.get(theClass);
       Map index = new HashMap();
       copyNonPrivateMethods(currentIndex,index);
       for (Iterator iter = interfaces.iterator(); iter.hasNext();) {
           Class iClass = (Class) iter.next();
           Map methodIndex = (Map) classMethodIndex.get(iClass);
           if (methodIndex==null || methodIndex.size()==0) {
               classMethodIndex.put(iClass,index);
               continue;
           }
           copyNonPrivateMethods(currentIndex,methodIndex);
       }
   }
   
   private static void makeInterfaceSet(Class c, Set s) {
       if (c==null) return;
       Class[] interfaces = c.getInterfaces();
       for (int i = 0; i < interfaces.length; i++) {
           if (!s.contains(interfaces[i])) {
               s.add(interfaces[i]);
               makeInterfaceSet(interfaces[i],s);
           }
       }
       makeInterfaceSet(c.getSuperclass(),s);
   }
   
   private void copyNonPrivateMethods(Map from, Map to) {
       for (Iterator iterator = from.entrySet().iterator(); iterator.hasNext();) {
           Map.Entry element = (Map.Entry) iterator.next();
           List oldList = (List) element.getValue();
           List newList = (List) to.get(element.getKey());
           if (newList==null) {
               to.put(element.getKey(),new ArrayList(oldList));
           } else {
               addNonPrivateMethods(newList,oldList);
           }
       }
   }
   
   private void connectMultimethods(List superClasses){
       superClasses = DefaultGroovyMethods.reverse(superClasses);
       Map last = null;
       for (Iterator iter = superClasses.iterator(); iter.hasNext();) {
           Class c = (Class) iter.next();
           Map methodIndex = (Map) classMethodIndex.get(c);
           if (methodIndex==last) continue;
           if (last!=null) copyNonPrivateMethods(last,methodIndex);
           last = methodIndex;
       }
   }
   
   private void inheritMethods(Collection superClasses, Map classMethodIndex){
       Map last = null;
       for (Iterator iter = superClasses.iterator(); iter.hasNext();) {
           Class c = (Class) iter.next();
           Map methodIndex = (Map) classMethodIndex.get(c);
           if (last!=null) {
               if (methodIndex.size()==0) {
                   classMethodIndex.put(c,last);
                   continue;
               }
               copyNonPrivateMethods(last,methodIndex);
           }
           last = methodIndex;
       }
   }

   private void addNonPrivateMethods(List newList, List oldList) {
       for (Iterator iter = oldList.iterator(); iter.hasNext();) {
           MetaMethod element = (MetaMethod) iter.next();
           if (element.isPrivate()) continue;
           addMethodToList(newList,element);
       }
   }

/**
    * @return all the normal instance methods avaiable on this class for the
    *         given name
    */
   private List getMethods(Class sender, String name, boolean isCallToSuper) {
       Map methodIndex;
       if (isCallToSuper) {
           methodIndex = (Map) classMethodIndexForSuper.get(sender);
       } else {
           methodIndex = (Map) classMethodIndex.get(sender);
       }   
       List answer;
       if (methodIndex!=null) {
           answer = (List) methodIndex.get(name);
           if (answer == null) answer = Collections.EMPTY_LIST;
       } else {
           answer = Collections.EMPTY_LIST;
       }
       
       if (!isCallToSuper && GroovyCategorySupport.hasCategoryInAnyThread()) {
           List used = GroovyCategorySupport.getCategoryMethods(sender, name);
           if (used != null) {
               answer = new ArrayList(answer);
               for (Iterator iter = used.iterator(); iter.hasNext();) {
                   MetaMethod element = (MetaMethod) iter.next();
                   removeMatchingMethod(answer,element);
               }
               answer.addAll(used);
           }
       }
       return answer;
   }

   /**
    * @return all the normal static methods avaiable on this class for the
    *         given name
    */
   private List getStaticMethods(Class sender, String name) {
       Map methodIndex = (Map) classStaticMethodIndex.get(sender);
       if (methodIndex == null) return Collections.EMPTY_LIST;
       List answer = (List) methodIndex.get(name);
       if (answer == null) return Collections.EMPTY_LIST;
       return answer;
   }

   public void addNewInstanceMethod(Method method) {
       NewInstanceMetaMethod newMethod = new NewInstanceMetaMethod(createMetaMethod(method));
       if (! newGroovyMethodsList.contains(newMethod)){
           newGroovyMethodsList.add(newMethod);
           addMetaMethod(newMethod);
       }
   }

   public void addNewStaticMethod(Method method) {
       NewStaticMetaMethod newMethod = new NewStaticMetaMethod(createMetaMethod(method));
       if (! newGroovyMethodsList.contains(newMethod)){
           newGroovyMethodsList.add(newMethod);
           addMetaMethod(newMethod);
       }
   }

   private void unwrap(Object[] arguments) {
       //
       // Temp code to ignore wrapped parameters
       // The New MOP will deal with these properly
       //
       for (int i = 0; i != arguments.length; i++) {
        if (arguments[i] instanceof Wrapper) {
          arguments[i] = ((Wrapper)arguments[i]).unwrap();
        }
       }       
   }
   
   
   /**
    * Invokes the given method on the object.
    * @deprecated
    */
   public Object invokeMethod(Object object, String methodName, Object[] originalArguments) {
       return invokeMethod(theClass,object,methodName,originalArguments,false,false);
   }
   
   
   /**
    * Invokes the given method on the object.
    *
    */
   public Object invokeMethod(Class sender, Object object, String methodName, Object[] originalArguments, boolean isCallToSuper, boolean fromInsideClass) {
       checkInitalised();
       if (object == null) {
           throw new NullPointerException("Cannot invoke method: " + methodName + " on null object");
       }              
       if (log.isLoggable(Level.FINER)){
           MetaClassHelper.logMethodCall(object, methodName, originalArguments);
       }
       Object[] arguments = originalArguments;
       if (arguments==null) arguments = EMPTY_ARGUMENTS;
       Class[] argClasses = MetaClassHelper.convertToTypeArray(arguments);
       unwrap(arguments);
       
       MetaMethod method = getMethodWithCaching(sender, methodName, argClasses, isCallToSuper);
       
       if (method==null && arguments.length==1 && arguments[0] instanceof List) {
           Object[] newArguments = ((List) arguments[0]).toArray();
           Class[] newArgClasses = MetaClassHelper.convertToTypeArray(newArguments);
           method = getMethodWithCaching(sender, methodName, newArgClasses, isCallToSuper);
           if (method!=null) {
               MethodKey methodKey = new DefaultMethodKey(sender, methodName, argClasses, isCallToSuper);
               method = new TransformMetaMethod(method) {
                   public Object invoke(Object object, Object[] arguments) {
                       Object firstArgument = arguments[0];
                       List list = (List) firstArgument;
                       arguments = list.toArray();
                       return super.invoke(object, arguments);
                   }
               };
               cacheInstanceMethod(methodKey, method);
               return invokeMethod(sender,object,methodName, originalArguments, isCallToSuper, fromInsideClass);
           }
       }

       boolean isClosure = object instanceof Closure;
       if (isClosure) {
           Closure closure = (Closure) object;
           Object delegate = closure.getDelegate();
           Object owner = closure.getOwner();
           
           
           if ("call".equals(methodName) || "doCall".equals(methodName)) {
               if (object.getClass()==MethodClosure.class) {
                   MethodClosure mc = (MethodClosure) object;
                   methodName = mc.getMethod();
                   Class ownerClass = owner.getClass();
                   if (owner instanceof Class) ownerClass = (Class) owner;
                   MetaClass ownerMetaClass = registry.getMetaClass(ownerClass);
                   return ownerMetaClass.invokeMethod(ownerClass,owner,methodName,arguments,false,false);
               } else if (object.getClass()==CurriedClosure.class) {
                   CurriedClosure cc = (CurriedClosure) object;
                   // change the arguments for an uncurried call
                   arguments = cc.getUncurriedArguments(arguments);
                   Class ownerClass = owner.getClass();
                   if (owner instanceof Class) ownerClass = (Class) owner;
                   MetaClass ownerMetaClass = registry.getMetaClass(ownerClass);
                   return ownerMetaClass.invokeMethod(owner,methodName,arguments);
               }
           } else if ("curry".equals(methodName)) {
               return closure.curry(arguments);
           }

           if (method==null && owner!=closure) {
               Class ownerClass = owner.getClass();
               if (owner instanceof Class) ownerClass = (Class) owner;
               MetaClass ownerMetaClass = registry.getMetaClass(ownerClass);
               method = ownerMetaClass.pickMethod(methodName,argClasses);
               if (method!=null) return ownerMetaClass.invokeMethod(owner,methodName,originalArguments);
           }
           if (method==null && delegate!=closure && delegate!=null) {
               Class delegateClass = delegate.getClass();
               if (delegate instanceof Class) delegateClass = (Class) delegate;
               MetaClass delegateMetaClass = registry.getMetaClass(delegateClass);
               method = delegateMetaClass.pickMethod(methodName,argClasses);
               if (method!=null) return delegateMetaClass.invokeMethod(delegate,methodName,originalArguments);
           }
           if (method==null) {
               // still no methods found, test if delegate or owner are GroovyObjects
               // and invoke the method on them if so.
               MissingMethodException last = null;
               if (owner!=closure && (owner instanceof GroovyObject)) {
                   try {
                       GroovyObject go = (GroovyObject) owner;
                       return go.invokeMethod(methodName,originalArguments);
                   } catch (MissingMethodException mme) {
                       if (last==null) last = mme;
                   }
               }
               if (delegate!=closure && (delegate instanceof GroovyObject)) {
                   try {
                       GroovyObject go = (GroovyObject) delegate;
                       return go.invokeMethod(methodName,originalArguments);
                   } catch (MissingMethodException mme) {
                       last = mme;
                   }
               }
               if (last!=null) throw last;
           }

       }

       if (method != null) {
           return MetaClassHelper.doMethodInvoke(object, method, arguments);
       } else {
           // if no method was found, try to find a closure defined as a field of the class and run it
           try {
               Object value = this.getProperty(object, methodName);
               if (value instanceof Closure) {  // This test ensures that value != this If you ever change this ensure that value != this
                   Closure closure = (Closure) value;
                   MetaClass delegateMetaClass = closure.getMetaClass();
                   return delegateMetaClass.invokeMethod(closure.getClass(),closure,"doCall",originalArguments,false,fromInsideClass);
               }
           } catch (MissingPropertyException mpe) {}

           throw new MissingMethodException(methodName, theClass, originalArguments, false);
       }
   }
   
   public MetaMethod getMethodWithCaching(Class sender, String methodName, Class[] arguments, boolean isCallToSuper) {
       // lets try use the cache to find the method
       if (GroovyCategorySupport.hasCategoryInAnyThread() && !isCallToSuper) {
           return getMethodWithoutCaching(sender, methodName, arguments, isCallToSuper);
       } else {
           MethodKey methodKey = new DefaultMethodKey(sender, methodName, arguments, isCallToSuper);
           MetaMethod method = (MetaMethod) methodCache.get(methodKey);
           if (method == null) {
               method = getMethodWithoutCaching(sender, methodName, arguments, isCallToSuper);
               cacheInstanceMethod(methodKey, method);
           }
           return method;
       }
   }
   
   protected void cacheInstanceMethod(MethodKey key, MetaMethod method) {
       if (method != null && method.isCacheable()) {
           methodCache.put(key, method);
       }
   }

   protected void cacheStaticMethod(MethodKey key, MetaMethod method) {
       if (method != null && method.isCacheable()) {
           staticMethodCache.put(key, method);
       }
   }

   
   public Constructor retrieveConstructor(Class[] arguments) {
       Constructor constructor = (Constructor) chooseMethod("<init>", constructors, arguments, false);
       if (constructor != null) {
           return constructor;
       }
       constructor = (Constructor) chooseMethod("<init>", constructors, arguments, true);
       if (constructor != null) {
           return constructor;
       }
       return null;
   }

   public MetaMethod retrieveStaticMethod(String methodName, Class[] arguments) {
       MethodKey methodKey = new DefaultMethodKey(theClass, methodName, arguments, false);
       MetaMethod method = (MetaMethod) staticMethodCache.get(methodKey);
       if (method == null) {
           method = pickStaticMethod(theClass,methodName, arguments);
           cacheStaticMethod(methodKey, method);
       }
       return method;
   }

   public MetaMethod getMethodWithoutCaching(Class sender, String methodName, Class[] arguments, boolean isCallToSuper) {
       MetaMethod method = null;
       List methods = getMethods(sender,methodName,isCallToSuper);
       if (methods!=null && !methods.isEmpty()) {
           method = (MetaMethod) chooseMethod(methodName, methods, arguments, false);
       }
       return method;
   }

   public Object invokeStaticMethod(Object object, String methodName, Object[] arguments) {
       checkInitalised();
       if (log.isLoggable(Level.FINER)){
           MetaClassHelper.logMethodCall(object, methodName, arguments);
       }
       
       Class sender = object.getClass();
       if (object instanceof Class) sender = (Class) object;
       if (sender!=theClass) {
           MetaClass mc = registry.getMetaClass(sender);
           return mc.invokeStaticMethod(sender,methodName,arguments);
       }
       if (sender==Class.class) {
           return invokeMethod(object,methodName,arguments);
       }
       
       if (arguments==null) arguments = EMPTY_ARGUMENTS;
       Class[] argClasses = MetaClassHelper.convertToTypeArray(arguments);
       unwrap(arguments);
       
       // lets try use the cache to find the method
       MethodKey methodKey = new DefaultMethodKey(sender, methodName, argClasses, false);
       MetaMethod method = (MetaMethod) staticMethodCache.get(methodKey);
       if (method == null) {
           method = pickStaticMethod(sender, methodName, argClasses);
           cacheStaticMethod(methodKey.createCopy(), method);
       }

       if (method != null) {
           return MetaClassHelper.doMethodInvoke(object, method, arguments);
       }

       throw new MissingMethodException(methodName, sender, arguments, true);
   }
   
   private MetaMethod pickStaticMethod(Class sender, String methodName, Class[] arguments) {
       MetaMethod method = null;
       List methods = getStaticMethods(sender,methodName);

       if (!methods.isEmpty()) {
           method = (MetaMethod) chooseMethod(methodName, methods, arguments, false);
       }
       if (method == null && theClass != Class.class) {
           MetaClass classMetaClass = registry.getMetaClass(Class.class);
           method = classMetaClass.pickMethod(methodName, arguments);
       }
       if (method == null) {
           method = (MetaMethod) chooseMethod(methodName, methods, MetaClassHelper.convertToTypeArray(arguments), true);
       }
       return method;
   }

   public Object invokeConstructor(Object[] arguments) {
       return invokeConstructor(theClass,arguments,false);
   }

   public int selectConstructorAndTransformArguments(int numberOfCosntructors, Object[] arguments) {
       //TODO: that is just a quick prototype, not the real thing!
       if (numberOfCosntructors != constructors.size()) {
           throw new IncompatibleClassChangeError("the number of constructors during runtime and compile time for "+
               this.theClass.getName()+" do not match. Expected "+numberOfCosntructors+" but got "+constructors.size());
       }
       
       if (arguments==null) arguments = EMPTY_ARGUMENTS;
       Class[] argClasses = MetaClassHelper.convertToTypeArray(arguments);
       unwrap(arguments);       
       Constructor constructor = (Constructor) chooseMethod("<init>", constructors, argClasses, false);
       if (constructor == null) {
           constructor = (Constructor) chooseMethod("<init>", constructors, argClasses, true);
       }
       if (constructor==null) {
           throw new GroovyRuntimeException(
                   "Could not find matching constructor for: "
                       + theClass.getName()
                       + "("+InvokerHelper.toTypeString(arguments)+")");
       }
       List l = new ArrayList(constructors);
       Comparator comp = new Comparator() {
           public int compare(Object arg0, Object arg1) {
               Constructor c0 = (Constructor) arg0;
               Constructor c1 = (Constructor) arg1;
               String descriptor0 = BytecodeHelper.getMethodDescriptor(Void.TYPE, c0.getParameterTypes()); 
               String descriptor1 = BytecodeHelper.getMethodDescriptor(Void.TYPE, c1.getParameterTypes());
               return descriptor0.compareTo(descriptor1);
           }            
       };
       Collections.sort(l,comp);
       int found = -1;
       for (int i=0; i<l.size(); i++) {
           if (l.get(i)!=constructor) continue;
           found = i;
           break;
       }
       // NOTE: must be changed to "1 |" if constructor was vargs
       int ret = 0 | (found << 8);
       return ret;
   }
   
   /**
    * checks if the initialisation of the class id complete.
    * This method should be called as a form of assert, it is no
    * way to test if there is still initialisation work to be done. 
    * Such logic must be implemented in a different way.
    * @throws IllegalStateException if the initialisation is incomplete yet
    */
   protected void checkInitalised() {
       if (!isInitialized())
           throw new IllegalStateException(
                   "initialize must be called for meta " +
                   "class of "+ theClass + 
                   "("+this.getClass() + ") " +
                   "to complete initialisation process " +
                   "before any invocation or field/property " +
                   "access can be done");
   }
   
   private Object invokeConstructor(Class at, Object[] arguments, boolean setAccessible) {
       checkInitalised();
       if (arguments==null) arguments = EMPTY_ARGUMENTS;
       Class[] argClasses = MetaClassHelper.convertToTypeArray(arguments);
       unwrap(arguments);       
       Constructor constructor = (Constructor) chooseMethod("<init>", constructors, argClasses, false);
       if (constructor != null) {
           return doConstructorInvoke(at, constructor, arguments, true);
       }
       constructor = (Constructor) chooseMethod("<init>", constructors, argClasses, true);
       if (constructor != null) {
           return doConstructorInvoke(at, constructor, arguments, true);
       }

       if (arguments.length == 1) {
           Object firstArgument = arguments[0];
           if (firstArgument instanceof Map) {
               constructor = (Constructor) chooseMethod("<init>", constructors, MetaClassHelper.EMPTY_TYPE_ARRAY, false);
               if (constructor != null) {
                   Object bean = doConstructorInvoke(at, constructor, MetaClassHelper.EMPTY_ARRAY, true);
                   setProperties(bean, ((Map) firstArgument));
                   return bean;
               }
           }
       }
       throw new GroovyRuntimeException(
                   "Could not find matching constructor for: "
                       + theClass.getName()
                       + "("+InvokerHelper.toTypeString(arguments)+")");
   }

   /**
    * Sets a number of bean properties from the given Map where the keys are
    * the String names of properties and the values are the values of the
    * properties to set
    */
   public void setProperties(Object bean, Map map) {
       checkInitalised();
       for (Iterator iter = map.entrySet().iterator(); iter.hasNext();) {
           Map.Entry entry = (Map.Entry) iter.next();
           String key = entry.getKey().toString();

           Object value = entry.getValue();
           setProperty(bean, key, value);
       }
   }
   
   /**
    * @return the given property's value on the object
    */
   public Object getProperty(Class sender, Object object, String name, boolean useSuper, boolean fromInsideClass) {
       checkInitalised();
       
       //----------------------------------------------------------------------
       // handling of static
       //----------------------------------------------------------------------
       boolean isStatic = theClass != Class.class && object instanceof Class;
       if (isStatic && object != theClass) {
           MetaClass mc = registry.getMetaClass((Class) object);
           return mc.getProperty(sender,object,name,useSuper,false);
       }
    
       MetaMethod method = null;
       Object[] arguments = EMPTY_ARGUMENTS;

       //----------------------------------------------------------------------
       // getter
       //----------------------------------------------------------------------
       MetaProperty mp = getMetaProperty(sender,name,useSuper, isStatic);
       if (mp != null) {
           if (mp instanceof MetaBeanProperty) {
               MetaBeanProperty mbp = (MetaBeanProperty) mp;
               method = mbp.getGetter();
               mp = mbp.getField();
           } 
       }

       // check for a category method named like a getter 
       if (method==null && !useSuper && !isStatic && GroovyCategorySupport.hasCategoryInAnyThread()) {
           String getterName = "get"+MetaClassHelper.capitalize(name);
           method = getCategoryMethodGetter(sender,getterName,false);
       }

       //----------------------------------------------------------------------
       // field
       //----------------------------------------------------------------------
       if (method==null && mp!=null) {
           return mp.getProperty(object);
       }
       

       //----------------------------------------------------------------------
       // generic get method
       //----------------------------------------------------------------------       
       // check for a generic get method provided through a category
       if (method==null && !useSuper && !isStatic && GroovyCategorySupport.hasCategoryInAnyThread()) {
           method = getCategoryMethodGetter(sender,"get",true);
           if (method!=null) arguments = new Object[]{name};
       }

       // the generic method is valid, if available (!=null), if static or
       // if it is not static and we do no static access
       if (method==null && genericGetMethod != null && !(!genericGetMethod.isStatic() && isStatic)) {
           arguments = new Object[]{ name };
           method = genericGetMethod;
       } 
       
       //----------------------------------------------------------------------
       // special cases
       //----------------------------------------------------------------------
       if (method==null) {
           /** todo these special cases should be special MetaClasses maybe */
           if (theClass != Class.class && object instanceof Class) {
               MetaClass mc = registry.getMetaClass(Class.class);
               return mc.getProperty(Class.class,object,name,useSuper,false);
           } else if (object instanceof Collection) {
               return DefaultGroovyMethods.getAt((Collection) object, name);
           } else if (object instanceof Object[]) {
               return DefaultGroovyMethods.getAt(Arrays.asList((Object[]) object), name);
           } else {
               MetaMethod addListenerMethod = (MetaMethod) listeners.get(name);
               if (addListenerMethod != null) {
                   //TODO: one day we could try return the previously registered Closure listener for easy removal
                   return null;
               }
           }
       } else {
           
           //----------------------------------------------------------------------
           // executing the getter method 
           //----------------------------------------------------------------------
           return MetaClassHelper.doMethodInvoke(object,method,arguments);
       }
       
       //----------------------------------------------------------------------
       // error due to missing method/field
       //----------------------------------------------------------------------
       throw new MissingPropertyException(name, theClass);   
   }

   private MetaMethod getCategoryMethodGetter(Class sender, String name, boolean useLongVersion) {
       List possibleGenericMethods = GroovyCategorySupport.getCategoryMethods(sender, name);
       if (possibleGenericMethods != null) {
           for (Iterator iter = possibleGenericMethods.iterator(); iter.hasNext();) {
               MetaMethod mmethod = (MetaMethod) iter.next();
               Class[] paramTypes = mmethod.getParameterTypes();
               if (useLongVersion) {
                   if (paramTypes.length==1 && paramTypes[0] == String.class) {
                       return mmethod;
                   }
               } else {
                   if (paramTypes.length==0) return mmethod;
               }
           }
       }
       return null;
   }
   
   private MetaMethod getCategoryMethodSetter(Class sender, String name, boolean useLongVersion) {
       List possibleGenericMethods = GroovyCategorySupport.getCategoryMethods(sender, name);
       if (possibleGenericMethods != null) {
           for (Iterator iter = possibleGenericMethods.iterator(); iter.hasNext();) {
               MetaMethod mmethod = (MetaMethod) iter.next();
               Class[] paramTypes = mmethod.getParameterTypes();
               if (useLongVersion) {
                   if (paramTypes.length==2 && paramTypes[0] == String.class) {
                       return mmethod;
                   }
               } else {
                   if (paramTypes.length==1) return mmethod;
               }
           }
       }
       return null;
   }

   /**
    * Get all the properties defined for this type
    * @return a list of MetaProperty objects
    */
   public List getProperties() {
       checkInitalised();
       Map propertyMap = (Map) classPropertyIndex.get(theClass);
       // simply return the values of the metaproperty map as a List
       List ret = new ArrayList(propertyMap.size());
       for (Iterator iter = propertyMap.values().iterator(); iter.hasNext();) {
           MetaProperty element = (MetaProperty) iter.next();
           if (element instanceof MetaFieldProperty) continue;
           // filter out DGM beans
           if (element instanceof MetaBeanProperty) {
               MetaBeanProperty mp = (MetaBeanProperty) element;
               boolean setter = true;
               boolean getter = true;
               if (mp.getGetter()==null || mp.getGetter() instanceof NewInstanceMetaMethod) {
                   getter=false;
               }
               if (mp.getSetter()==null || mp.getSetter() instanceof NewInstanceMetaMethod) {
                   setter=false;
               }
               if (!setter && !getter) continue;
               if (!setter && mp.getSetter()!=null) {
                   element = new MetaBeanProperty(mp.getName(),mp.getType(),mp.getGetter(),null);
               }
               if (!getter && mp.getGetter()!=null) {
                   element = new MetaBeanProperty(mp.getName(),mp.getType(), null, mp.getSetter());
               }
           }
           ret.add(element);
       }
       return ret;
   }
   
   private MetaMethod findPropertyMethod(List methods, boolean isGetter) {
       LinkedList ret = new LinkedList();
       for (Iterator iter = methods.iterator(); iter.hasNext();) {
           MetaMethod element = (MetaMethod) iter.next();
           if ( !isGetter && 
                //(element.getReturnType() == Void.class || element.getReturnType() == Void.TYPE) && 
                element.getParameterTypes().length == 1)
           {
               ret.add(element);
           } 
           if ( isGetter &&
                !(element.getReturnType() == Void.class || element.getReturnType() == Void.TYPE) && 
                element.getParameterTypes().length == 0)
           {
               ret.add(element);
           }
       }
       if (ret.size() == 0) return null;
       if (ret.size() == 1) return (MetaMethod) ret.getFirst();
       
       // we found multiple matching methods
       // this is a problem, because we can use only one
       // if it is a getter, then use the most general return 
       // type to decide which method to use. If it is a setter 
       // we use the type of the first parameter 
       MetaMethod method = null;
       int distance = -1;
       for (Iterator iter = ret.iterator(); iter.hasNext();) {
           MetaMethod element = (MetaMethod) iter.next();
           Class c;
           if (isGetter) {
               c = element.getReturnType();
           } else {
               c = element.getParameterTypes()[0];
           }
           int localDistance = distanceToObject(c);
           //TODO: maybe implement the case localDistance==distance
           if (distance==-1 || distance>localDistance) {
               distance = localDistance;
               method = element;
           } 
       }
       return method;
   }
   
   private static int distanceToObject(Class c) {
       int count;
       for (count=0; c!=null; count++) {
           c=c.getSuperclass();           
       }
       return count;
   }
   
   
   /**
    * This will build up the property map (Map of MetaProperty objects, keyed on
    * property name).
    */
   private void setupProperties(PropertyDescriptor[] propertyDescriptors) {
       LinkedList superClasses = getSuperClasses();
       Set interfaces = new HashSet();
       makeInterfaceSet(theClass,interfaces);
       
       // if this an Array, then add the special read-only "length" property
       if (theClass.isArray()) {
           Map map = new HashMap();
           map.put("length", arrayLengthProperty);
           classPropertyIndex.put(theClass,map);
       }
              
       inheritStaticInterfaceFields(superClasses, interfaces);       
       inheritFields(superClasses);
       applyPropertyDescriptors(propertyDescriptors);
       
       applyStrayPropertyMethods(superClasses,classMethodIndex,classPropertyIndex);
       applyStrayPropertyMethods(superClasses,classMethodIndexForSuper,classPropertyIndexForSuper);
       
       copyClassPropertyIndexForSuper();
       makeStaticPropertyIndex();
   }
   
   private void makeStaticPropertyIndex() {
       Map propertyMap = (Map) classPropertyIndex.get(theClass);
       for (Iterator iter = propertyMap.entrySet().iterator(); iter.hasNext();) {
           Map.Entry entry = (Map.Entry) iter.next();
           MetaProperty mp = (MetaProperty) entry.getValue();
           if (mp instanceof MetaFieldProperty) {
               MetaFieldProperty mfp = (MetaFieldProperty) mp;
               if (!mfp.isStatic()) continue;
           } else if (mp instanceof MetaBeanProperty) {
               MetaBeanProperty mbp = (MetaBeanProperty) mp;
               boolean getter = mbp.getGetter()==null || mbp.getGetter().isStatic();
               boolean setter = mbp.getSetter()==null || mbp.getSetter().isStatic();
               boolean field = mbp.getField()==null || mbp.getField().isStatic();
               
               if (!getter && !setter && !field) {
                   continue;
               } else if (setter && getter) {
                   if (field) {
                       mp = mbp; // nothing to do
                   } else {
                       mp = new MetaBeanProperty(mbp.getName(),mbp.getType(),mbp.getGetter(),mbp.getSetter());
                   }
               } else if (getter && !setter) {
                   if (mbp.getGetter()==null) {
                       mp = mbp.getField();
                   } else {
                       MetaBeanProperty newmp = new MetaBeanProperty(mbp.getName(),mbp.getType(),mbp.getGetter(),null);
                       if (field) newmp.setField(mbp.getField());
                       mp = newmp;
                   }
               } else if (setter && !getter) {
                   if (mbp.getSetter()==null) {
                       mp = mbp.getField();
                   } else {
                       MetaBeanProperty newmp = new MetaBeanProperty(mbp.getName(),mbp.getType(),null,mbp.getSetter());
                       if (field) newmp.setField(mbp.getField());
                       mp = newmp;
                   }
               } else if (field) {
                   mp = mbp.getField();
               }
           } else {
               continue; // ignore all other types
           }
           if (mp==null) continue;
           staticPropertyIndex.put(entry.getKey(),mp);
       }
       
   }
   
   private void copyClassPropertyIndexForSuper() {
       for (Iterator iter = classPropertyIndex.entrySet().iterator(); iter.hasNext();) {
           Map.Entry entry = (Map.Entry) iter.next();
           HashMap newVal = new HashMap((Map)entry.getValue());
           classPropertyIndexForSuper.put(entry.getKey(),newVal);
       }
   }
   
   private Map getMap2MapNotNull(Map m, Object key) {
       Map ret = (Map) m.get(key);
       if (ret==null) {
           ret = new HashMap();
           m.put(key,ret);
       }
       return ret;
   }
   
   private void inheritStaticInterfaceFields(LinkedList superClasses, Set interfaces) {
       for (Iterator interfaceIter = interfaces.iterator(); interfaceIter.hasNext();) {
           Class iclass = (Class) interfaceIter.next();
           Map iPropertyIndex = getMap2MapNotNull(classPropertyIndex,iclass);
           addFields(iclass,iPropertyIndex);
           for (Iterator classIter = superClasses.iterator(); classIter.hasNext();) {
               Class sclass = (Class) classIter.next();
               if (! iclass.isAssignableFrom(sclass)) continue;
               Map sPropertyIndex = getMap2MapNotNull(classPropertyIndex,sclass);
               copyNonPrivateFields(iPropertyIndex,sPropertyIndex);
           }
       }
   }
   
   private void inheritFields(LinkedList superClasses) {
       Map last = null;
       for (Iterator iter = superClasses.iterator(); iter.hasNext();) {
           Class klass = (Class) iter.next();
           Map propertyIndex = getMap2MapNotNull(classPropertyIndex,klass);
           if (last != null) {
               copyNonPrivateFields(last,propertyIndex);
           }
           last = propertyIndex;
           addFields(klass,propertyIndex);
       }   
   }
   
   private void addFields(final Class klass, Map propertyIndex) {
       Field[] fields = (Field[]) AccessController.doPrivileged(new  PrivilegedAction() {
           public Object run() {
               return klass.getDeclaredFields();
           }
       });
       for(int i = 0; i < fields.length; i++) {
           MetaFieldProperty mfp = new MetaFieldProperty(fields[i]);
           propertyIndex.put(fields[i].getName(), mfp);
       }
   }

   private void copyNonPrivateFields(Map from, Map to) {
       for (Iterator iter = from.entrySet().iterator(); iter.hasNext();) {
           Map.Entry entry = (Map.Entry) iter.next();
           MetaFieldProperty mfp = (MetaFieldProperty) entry.getValue();
           if (!Modifier.isPublic(mfp.getModifiers()) && !Modifier.isProtected(mfp.getModifiers())) continue;
           to.put(entry.getKey(),mfp);
       }
   }
   
   private void applyStrayPropertyMethods(LinkedList superClasses, Map classMethodIndex, Map classPropertyIndex) {
       // now look for any stray getters that may be used to define a property
       for (Iterator iter = superClasses.iterator(); iter.hasNext();) {
           Class klass = (Class) iter.next();
           Map methodIndex = (Map) classMethodIndex.get(klass);
           Map propertyIndex = getMap2MapNotNull(classPropertyIndex,klass);
           for (Iterator nameMethodIterator = methodIndex.entrySet().iterator(); nameMethodIterator.hasNext();) {
               Map.Entry entry = (Map.Entry) nameMethodIterator.next();
               String methodName = (String) entry.getKey();
               // name too sort?
               if (methodName.length() < 4) continue;
               //possible getter/setter
               boolean isGetter = methodName.startsWith("get");
               boolean isSetter = methodName.startsWith("set");
               if (!isGetter && !isSetter) continue;
               
               // get the name of the property
               String propName = methodName.substring(3,4).toLowerCase() + methodName.substring(4);
               MetaMethod propertyMethod = findPropertyMethod((List) entry.getValue(), isGetter);
               if (propertyMethod==null) continue;
               
               createMetaBeanProperty(propertyIndex, propName, isGetter, propertyMethod);
           }
       }
   }
   
   private void createMetaBeanProperty(Map propertyIndex, String propName, boolean isGetter, MetaMethod propertyMethod){
       // is this property already accounted for?
       MetaProperty mp = (MetaProperty) propertyIndex.get(propName);
       if (mp == null) {
           if (isGetter) {
               mp = new MetaBeanProperty(propName,
                       propertyMethod.getReturnType(),
                       propertyMethod, null);
           } else {
               //isSetter
               mp = new MetaBeanProperty(propName,
                       propertyMethod.getParameterTypes()[0],
                       null, propertyMethod);
           }
       } else {
           MetaBeanProperty mbp;
           MetaFieldProperty mfp;
           if (mp instanceof MetaBeanProperty) {
               mbp = (MetaBeanProperty) mp;
               mfp = mbp.getField();
           } else if (mp instanceof MetaFieldProperty){
               mfp = (MetaFieldProperty) mp;
               mbp = new MetaBeanProperty(propName,
                       mfp.getType(),
                       null, null);
           } else {
               throw new GroovyBugError("unknown MetaProperty class used. Class is "+mp.getClass());
           }
           // we may have already found one for this name
           if (isGetter && mbp.getGetter()==null) {
               mbp.setGetter(propertyMethod);
           } else if (!isGetter && mbp.getSetter()==null) {
               mbp.setSetter(propertyMethod);
           }
           mbp.setField(mfp);
           mp = mbp;
       }
       propertyIndex.put(propName, mp);
   }

   private void applyPropertyDescriptors(PropertyDescriptor[] propertyDescriptors) {
       Map propertyMap = (Map) classPropertyIndex.get(theClass);
       // now iterate over the map of property descriptors and generate
       // MetaBeanProperty objects
       for(int i=0; i<propertyDescriptors.length; i++) {
           PropertyDescriptor pd = propertyDescriptors[i];
           
           // skip if the property type is unknown (this seems to be the case if the
           // property descriptor is based on a setX() method that has two parameters,
           // which is not a valid property)
           if(pd.getPropertyType() == null)
               continue;
           
           // get the getter method
           Method method = pd.getReadMethod();
           MetaMethod getter;
           if(method != null)
               getter = findMethod(method);
           else
               getter = null;
           
           // get the setter method
           MetaMethod setter;
           method = pd.getWriteMethod();
           if(method != null)
               setter = findMethod(method);
           else
               setter = null;
           
           // now create the MetaProperty object
           MetaBeanProperty mp = new MetaBeanProperty(pd.getName(), pd.getPropertyType(), getter, setter);
           
           //keep field
           MetaFieldProperty field = null;
           MetaProperty old = (MetaProperty) propertyMap.get(pd.getName());
           if (old!=null) {
               if (old instanceof MetaBeanProperty) {
                   field = ((MetaBeanProperty) old).getField();
               } else {
                   field = (MetaFieldProperty) old;
               }
               mp.setField(field);
           }
           
           // put it in the list
           // this will overwrite a possible field property
           propertyMap.put(pd.getName(), mp);
       }       
   }
   
   /**
    * Sets the property value on an object
    */
   public void setProperty(Class sender,Object object, String name, Object newValue, boolean useSuper, boolean fromInsideClass) {
       checkInitalised();
       
       //----------------------------------------------------------------------
       // handling of static
       //----------------------------------------------------------------------
       boolean isStatic = theClass != Class.class && object instanceof Class;
       if (isStatic && object != theClass) {
           MetaClass mc = registry.getMetaClass((Class) object);
           mc.getProperty(sender,object,name,useSuper,fromInsideClass);
           return;
       }
       
       //----------------------------------------------------------------------
       // Unwrap wrapped values fo now - the new MOP will handle them properly
       //----------------------------------------------------------------------
       if (newValue instanceof Wrapper) newValue = ((Wrapper)newValue).unwrap();
       
       
       MetaMethod method = null;
       Object[] arguments = null;

       //----------------------------------------------------------------------
       // setter
       //----------------------------------------------------------------------
       MetaProperty mp = getMetaProperty(sender,name,useSuper, isStatic);
       MetaProperty field = null;
       if (mp != null) {
           if (mp instanceof MetaBeanProperty) {
               MetaBeanProperty mbp = (MetaBeanProperty) mp;
               method = mbp.getSetter();
               if (method!=null) arguments = new Object[] { newValue };
               field = mbp.getField();
           } else {
               field = mp;
           }
       }
       
       // check for a category method named like a setter 
       if (!useSuper && !isStatic && GroovyCategorySupport.hasCategoryInAnyThread()) {
           String getterName = "set"+MetaClassHelper.capitalize(name);
           method = getCategoryMethodSetter(sender,getterName,false);
           if (method!=null) arguments = new Object[] { newValue };
       }

       //----------------------------------------------------------------------
       // listener method
       //----------------------------------------------------------------------
       boolean ambigousListener = false;
       boolean usesProxy = false;
       if (method==null) {
           method = (MetaMethod) listeners.get(name);
           ambigousListener = method == AMBIGOUS_LISTENER_METHOD;
           if ( method != null && 
                !ambigousListener &&
                newValue instanceof Closure) 
           {
               // lets create a dynamic proxy
               Object proxy =
                   MetaClassHelper.createListenerProxy(method.getParameterTypes()[0], name, (Closure) newValue);
               arguments = new Object[] { proxy };
               newValue = proxy;
               usesProxy = true;
           } else {
               method = null;
           }
       }
       
       //----------------------------------------------------------------------
       // field
       //----------------------------------------------------------------------
       if (method==null && field!=null) {
           field.setProperty(object,newValue);
           return;
       }       

       //----------------------------------------------------------------------
       // generic set method
       //----------------------------------------------------------------------       
       // check for a generic get method provided through a category
       if (method==null && !useSuper && !isStatic && GroovyCategorySupport.hasCategoryInAnyThread()) {
           method = getCategoryMethodSetter(sender,"set",true);
           if (method!=null) arguments = new Object[]{name,newValue};
       }

       // the generic method is valid, if available (!=null), if static or
       // if it is not static and we do no static access
       if (method==null && genericSetMethod != null && !(!genericSetMethod.isStatic() && isStatic)) {
           arguments = new Object[]{ name, newValue };
           method = genericSetMethod;
       } 
       
       //----------------------------------------------------------------------
       // executing the getter method 
       //----------------------------------------------------------------------
       if (method!=null) {
           if (arguments.length==1) {
               newValue = DefaultTypeTransformation.castToType(
                       newValue,
                       method.getParameterTypes()[0]);
               arguments[0] = newValue;
           } else {
               newValue = DefaultTypeTransformation.castToType(
                       newValue,
                       method.getParameterTypes()[1]);
               arguments[1] = newValue;
           }
           MetaClassHelper.doMethodInvoke(object,method,arguments);
           return;
       }
           
       //----------------------------------------------------------------------
       // error due to missing method/field
       //----------------------------------------------------------------------
       if (ambigousListener){
           throw new GroovyRuntimeException("There are multiple listeners for the property "+name+". Please do not use the bean short form to access this listener.");
       } 
       throw new MissingPropertyException(name, theClass);   
   }
   
   private MetaProperty getMetaProperty(Class clazz, String name, boolean useSuper, boolean useStatic) {
       Map propertyMap;
       if (useStatic) {
           propertyMap = staticPropertyIndex;
       } else if (useSuper){
           propertyMap = (Map) classPropertyIndexForSuper.get(clazz);
       } else {
           propertyMap = (Map) classPropertyIndex.get(clazz);
       }
       if (propertyMap==null) {
           if (clazz!=theClass) {
               return getMetaProperty(theClass,name,useSuper, useStatic);
           } else {
               return null;
           }           
       }
       return (MetaProperty) propertyMap.get(name);
   }


   /**
    * Looks up the given attribute (field) on the given object
    */
   public Object getAttribute(Class sender, Object object, String attribute, boolean useSuper, boolean fromInsideClass) {
       checkInitalised();
       
       boolean isStatic = theClass != Class.class && object instanceof Class;
       if (isStatic && object != theClass) {
           MetaClass mc = registry.getMetaClass((Class) object);
           return mc.getAttribute(sender,object,attribute,useSuper);
       }
    
       MetaProperty mp = getMetaProperty(sender,attribute,useSuper, isStatic);
       
       if (mp != null) {
           if (mp instanceof MetaBeanProperty) {
               MetaBeanProperty mbp = (MetaBeanProperty) mp;
               mp = mbp.getField();
           }
           try {
               // delegate the get operation to the metaproperty
               if (mp != null) return mp.getProperty(object);
           } catch(Exception e) {
               throw new GroovyRuntimeException("Cannot read field: " + attribute,e);
           }
       }
       
       throw new MissingFieldException(attribute, theClass);
   }

   /**
    * Sets the given attribute (field) on the given object
    */
   public void setAttribute(Class sender, Object object, String attribute, Object newValue, boolean useSuper, boolean fromInsideClass) {
       checkInitalised();
       
       boolean isStatic = theClass != Class.class && object instanceof Class;
       if (isStatic && object != theClass) {
           MetaClass mc = registry.getMetaClass((Class) object);
           mc.setAttribute(sender,object,attribute,newValue,useSuper,fromInsideClass);
           return;
       }
    
       MetaProperty mp = getMetaProperty(sender,attribute,useSuper, isStatic);
       
       if (mp != null) {
           if (mp instanceof MetaBeanProperty) {
               MetaBeanProperty mbp = (MetaBeanProperty) mp;
               mp = mbp.getField();
           }
           if (mp != null) {
               mp.setProperty(object,newValue);
               return;
           }
       }
       
       throw new MissingFieldException(attribute, theClass);
   }

   public ClassNode getClassNode() {
       if (classNode == null && GroovyObject.class.isAssignableFrom(theClass)) {
           // lets try load it from the classpath
           String className = theClass.getName();
           String groovyFile = className;
           int idx = groovyFile.indexOf('$');
           if (idx > 0) {
               groovyFile = groovyFile.substring(0, idx);
           }
           groovyFile = groovyFile.replace('.', '/') + ".groovy";

           //System.out.println("Attempting to load: " + groovyFile);
           URL url = theClass.getClassLoader().getResource(groovyFile);
           if (url == null) {
               url = Thread.currentThread().getContextClassLoader().getResource(groovyFile);
           }
           if (url != null) {
               try {

                   /**
                    * todo there is no CompileUnit in scope so class name
                    * checking won't work but that mostly affects the bytecode
                    * generation rather than viewing the AST
                    */
                   CompilationUnit.ClassgenCallback search = new CompilationUnit.ClassgenCallback() {
                       public void call( ClassVisitor writer, ClassNode node ) {
                           if( node.getName().equals(theClass.getName()) ) {
                               MetaClassImpl.this.classNode = node;
                           }
                       }
                   };

                   final ClassLoader parent = theClass.getClassLoader();
                   GroovyClassLoader gcl = (GroovyClassLoader) AccessController.doPrivileged(new PrivilegedAction() {
                       public Object run() {
                           return new GroovyClassLoader(parent);
                       }
                   });
                   CompilationUnit unit = new CompilationUnit( );
                   unit.setClassgenCallback( search );
                   unit.addSource( url );
                   unit.compile( Phases.CLASS_GENERATION );
               }
               catch (Exception e) {
                   throw new GroovyRuntimeException("Exception thrown parsing: " + groovyFile + ". Reason: " + e, e);
               }
           }

       }
       return classNode;
   }

   public String toString() {
       return super.toString() + "[" + theClass + "]";
   }

   // Implementation methods
   //-------------------------------------------------------------------------
   
   /**
    * Adds all the methods declared in the given class to the metaclass
    * ignoring any matching methods already defined by a derived class
    *
    * @param theClass
    */
   private void addMethods(final Class theClass) {
       Map methodIndex = (Map) classMethodIndex.get(theClass);
       if (methodIndex==null) {
           methodIndex = new HashMap();
           classMethodIndex.put(theClass,methodIndex);
       }
       // add methods directly declared in the class
       Method[] methodArray = (Method[]) AccessController.doPrivileged(new  PrivilegedAction() {
               public Object run() {
                   return theClass.getDeclaredMethods();
               }
           });
       for (int i = 0; i < methodArray.length; i++) {
           Method reflectionMethod = methodArray[i];
           if ( reflectionMethod.getName().indexOf('+') >= 0 ) {
               // Skip Synthetic methods inserted by JDK 1.5 compilers and later
               continue;
           } else if (Modifier.isAbstract(reflectionMethod.getModifiers())) {
               continue;
           }
           MetaMethod method = createMetaMethod(reflectionMethod);
           addMetaMethod(method);
       }
       // add methods declared by DGM
       List methods = registry.getInstanceMethods();
       for (Iterator iter = methods.iterator(); iter.hasNext();) {
           Method element = (Method) iter.next();
           if (element.getParameterTypes()[0]!=theClass) continue;
           addNewInstanceMethod(element);
       }
       // add static methods declared by DGM
       methods = registry.getStaticMethods();
       for (Iterator iter = methods.iterator(); iter.hasNext();) {
           Method element = (Method) iter.next();
           if (element.getParameterTypes()[0]!=theClass) continue;
           addNewStaticMethod(element);
       }
   }
   
   private void addToClassMethodIndex(MetaMethod method, Map classMethodIndex) {
       Map methodIndex = (Map) classMethodIndex.get(method.getDeclaringClass());
       if (methodIndex==null) {
           methodIndex = new HashMap();
           classMethodIndex.put(method.getDeclaringClass(),methodIndex);
       }
       String name = method.getName();
       List list = (List) methodIndex.get(name);
       if (list == null) {
           list = new ArrayList();
           methodIndex.put(name, list);
           list.add(method);
       } else {
           addMethodToList(list,method);
       }
   }

   /**
    * adds a MetaMethod to this class. WARNING: this method will not
    * do the neccessary steps for multimethod logic and using this
    * method doesn't mean, that a method added here is replacing another
    * method from a parent class completely. These steps are usually done
    * by initalize, which means if you need these steps, you have to add
    * the method before running initialize the first time.
    * @see #initialize() 
    * @param method the MetaMethod
    */
   protected void addMetaMethod(MetaMethod method) {
       if (isInitialized()) {
           throw new RuntimeException("Already initialized, cannot add new method: " + method);
       }
       if (isGenericGetMethod(method) && genericGetMethod == null) {
           genericGetMethod = method;
       }
       else if (MetaClassHelper.isGenericSetMethod(method) && genericSetMethod == null) {
           genericSetMethod = method;
       }
       if (method.isStatic()) {
           addToClassMethodIndex(method,classStaticMethodIndex);
       }
       addToClassMethodIndex(method,classMethodIndex);
   }
   
   protected boolean isInitialized(){
       return initialized;
   }
   
   private void addMethodToList(List list, MetaMethod method) {
       MetaMethod match = removeMatchingMethod(list,method);
       if (match==null) {
           list.add(method);
       } else if (match.isPrivate()){
           // do not overwrite private methods
           // Note: private methods from parent classes are not shown here,
           // but when doing the multimethod connection step, we overwrite
           // methods of the parent class with methods of a subclass and
           // in that case we want to keep the private methods
           list.add(match);
       } else {
           Class methodC = method.getDeclaringClass();
           Class matchC = match.getDeclaringClass();
           if (methodC == matchC){
               if (method instanceof NewInstanceMetaMethod) {
                   // let DGM replace existing methods
                   list.add(method);
               } else {
                   list.add(match);
               }               
           } else if (MetaClassHelper.isAssignableFrom(methodC,matchC)){
               list.add(match);
           } else {
              list.add(method);
           }
       }
   }
   
   /**
    * remove a method of the same matching prototype was found in the list
    */
   private MetaMethod removeMatchingMethod(List list, MetaMethod method) {
       for (Iterator iter = list.iterator(); iter.hasNext();) {
           MetaMethod aMethod = (MetaMethod) iter.next();
           Class[] params1 = aMethod.getParameterTypes();
           Class[] params2 = method.getParameterTypes();
           if (params1.length == params2.length) {
               boolean matches = true;
               for (int i = 0; i < params1.length; i++) {
                   if (params1[i] != params2[i]) {
                       matches = false;
                       break;
                   }
               }
               if (matches) {
                   iter.remove();
                   return (MetaMethod) aMethod;
               }
           }
       }
       return null;
   }

   /**
    * @return the matching method which should be found
    */
   private MetaMethod findMethod(Method aMethod) {
       List methods = getMethods(theClass,aMethod.getName(),false);
       for (Iterator iter = methods.iterator(); iter.hasNext();) {
           MetaMethod method = (MetaMethod) iter.next();
           if (method.isMethod(aMethod)) {
               return method;
           }
       }
       //log.warning("Creating reflection based dispatcher for: " + aMethod);
       return new ReflectionMetaMethod(aMethod);
   }

   /**
    * @return the getter method for the given object
    */
   private MetaMethod findGetter(Object object, String name) {
       List methods = getMethods(theClass,name,false);
       for (Iterator iter = methods.iterator(); iter.hasNext();) {
           MetaMethod method = (MetaMethod) iter.next();
           if (method.getParameterTypes().length == 0) {
               return method;
           }
       }
       return null;
   }

   /**
    * @return the Method of the given name with no parameters or null
    */
   private MetaMethod findStaticGetter(Class type, String name) {
       List methods = getStaticMethods(type, name);
       for (Iterator iter = methods.iterator(); iter.hasNext();) {
           MetaMethod method = (MetaMethod) iter.next();
           if (method.getParameterTypes().length == 0) {
               return method;
           }
       }

       /** todo dirty hack - don't understand why this code is necessary - all methods should be in the allMethods list! */
       try {
           Method method = type.getMethod(name, MetaClassHelper.EMPTY_TYPE_ARRAY);
           if ((method.getModifiers() & Modifier.STATIC) != 0) {
               return findMethod(method);
           }
           else {
               return null;
           }
       }
       catch (Exception e) {
           return null;
       }
   }
   
   private static Object doConstructorInvoke(final Class at, Constructor constructor, Object[] argumentArray, boolean setAccessible) {
       if (log.isLoggable(Level.FINER)) {
           MetaClassHelper.logMethodCall(constructor.getDeclaringClass(), constructor.getName(), argumentArray);
       }

       if (setAccessible) {
           // To fix JIRA 435
           // Every constructor should be opened to the accessible classes.
           final boolean accessible = MetaClassHelper.accessibleToConstructor(at, constructor);
           final Constructor ctor = constructor;
           AccessController.doPrivileged(new PrivilegedAction() {
               public Object run() {
                   ctor.setAccessible(accessible);
                   return null;
               }
           });
       }
       return MetaClassHelper.doConstructorInvoke(constructor,argumentArray);
   }

   /**
    * Chooses the correct method to use from a list of methods which match by
    * name.
    *
    * @param methods
    *            the possible methods to choose from
    * @param arguments
    *            the original argument to the method
    */
   private Object chooseMethod(String methodName, List methods, Class[] arguments, boolean coerce) {
       int methodCount = methods.size();
       if (methodCount <= 0) {
           return null;
       }
       else if (methodCount == 1) {
           Object method = methods.get(0);
           if (MetaClassHelper.isValidMethod(method, arguments, coerce)) {
               return method;
           }
           return null;
       }
       Object answer = null;
       if (arguments == null || arguments.length == 0) {
           answer = MetaClassHelper.chooseEmptyMethodParams(methods);
       }
       else if (arguments.length == 1 && arguments[0] == null) {
           answer = MetaClassHelper.chooseMostGeneralMethodWith1NullParam(methods);
       }
       else {
           List matchingMethods = new ArrayList();

           for (Iterator iter = methods.iterator(); iter.hasNext();) {
               Object method = iter.next();

               // making this false helps find matches
               if (MetaClassHelper.isValidMethod(method, arguments, coerce)) {
                   matchingMethods.add(method);
               }
           }
           if (matchingMethods.isEmpty()) {
               return null;
           }
           else if (matchingMethods.size() == 1) {
               return matchingMethods.get(0);
           }
           return chooseMostSpecificParams(methodName, matchingMethods, arguments);

       }
       if (answer != null) {
           return answer;
       }
       throw new GroovyRuntimeException(
           "Could not find which method to invoke from this list: "
               + methods
               + " for arguments: "
               + InvokerHelper.toString(arguments));
   }

   private Object chooseMostSpecificParams(String name, List matchingMethods, Class[] arguments) {

       long matchesDistance = -1;
       LinkedList matches = new LinkedList();
       for (Iterator iter = matchingMethods.iterator(); iter.hasNext();) {
           Object method = iter.next();
           Class[] paramTypes = MetaClassHelper.getParameterTypes(method);
           if (!MetaClassHelper.parametersAreCompatible(arguments, paramTypes)) continue;
           long dist = MetaClassHelper.calculateParameterDistance(arguments, paramTypes);
           if (dist==0) return method;
           if (matches.size()==0) {
               matches.add(method);
               matchesDistance = dist;
           } else if (dist<matchesDistance) {
               matchesDistance=dist;
               matches.clear();
               matches.add(method);
           } else if (dist==matchesDistance) {
               matches.add(method);
           }

       }
       if (matches.size()==1) {
           return matches.getFirst();
       }
       if (matches.size()==0) {
           return null;
       }

       //more than one matching method found --> ambigous!
       String msg = "Ambiguous method overloading for method ";
       msg+= theClass.getName()+"#"+name;
       msg+= ".\nCannot resolve which method to invoke for ";
       msg+= InvokerHelper.toString(arguments);
       msg+= " due to overlapping prototypes between:";
       for (Iterator iter = matches.iterator(); iter.hasNext();) {
           Class[] types=MetaClassHelper.getParameterTypes(iter.next());
           msg+= "\n\t"+InvokerHelper.toString(types);
       }
       throw new GroovyRuntimeException(msg);
   }

   private boolean isGenericGetMethod(MetaMethod method) {
       if (method.getName().equals("get")) {
           Class[] parameterTypes = method.getParameterTypes();
           return parameterTypes.length == 1 && parameterTypes[0] == String.class;
       }
       return false;
   }

   /**
    * Call this method when any mutation method is called, such as adding a new
    * method to this MetaClass so that any caching or bytecode generation can be
    * regenerated.
    */
   private synchronized void onMethodChange() {
       reflector = null;
   }

   
   public synchronized void initialize() {
       if (!isInitialized()) {
           fillMethodIndex();
           addProperties();
           initialized = true;
       }
       if (reflector == null) {
           generateReflector();
       }
   }

   private void addProperties()  {
       BeanInfo info;
       //     introspect
       try {
           info =(BeanInfo) AccessController.doPrivileged(new PrivilegedExceptionAction() {
               public Object run() throws IntrospectionException {
                   return Introspector.getBeanInfo(theClass);
               }
           });
       } catch (PrivilegedActionException pae) {
           throw new GroovyRuntimeException("exception while bean introspection",pae.getException());
       }
       PropertyDescriptor[] descriptors = info.getPropertyDescriptors();

       // build up the metaproperties based on the public fields, property descriptors,
       // and the getters and setters
       setupProperties(descriptors);
       
       EventSetDescriptor[] eventDescriptors = info.getEventSetDescriptors();
       for (int i = 0; i < eventDescriptors.length; i++) {
           EventSetDescriptor descriptor = eventDescriptors[i];
           Method[] listenerMethods = descriptor.getListenerMethods();
           for (int j = 0; j < listenerMethods.length; j++) {
               Method listenerMethod = listenerMethods[j];
               MetaMethod metaMethod = createMetaMethod(descriptor.getAddListenerMethod());
               String name = listenerMethod.getName();
               if (listeners.containsKey(name)) {
                   listeners.put(name, AMBIGOUS_LISTENER_METHOD);
               } else{
                   listeners.put(name, metaMethod);
               }
           }
       }    
   }

   private MetaMethod createMetaMethod(final Method method) {
       if (registry.useAccessible()) {
           AccessController.doPrivileged(new PrivilegedAction() {
               public Object run() {
                   method.setAccessible(true);
                   return null;
               }
           });
       }

       MetaMethod answer = new MetaMethod(method);
       if (isValidReflectorMethod(answer)) {
           allMethods.add(answer);
           answer.setMethodIndex(allMethods.size());
       }
       else {
           //log.warning("Creating reflection based dispatcher for: " + method);
           answer = new ReflectionMetaMethod(method);
       }

       if (useReflection) {
           //log.warning("Creating reflection based dispatcher for: " + method);
           return new ReflectionMetaMethod(method);
       }

       return answer;
   }

   private boolean isValidReflectorMethod(MetaMethod method) {
       // We cannot use a reflector if the method is private, protected, or package accessible only.
       if (!method.isPublic()) {
           return false;
       }
       // lets see if this method is implemented on an interface
       List interfaceMethods = getInterfaceMethods();
       for (Iterator iter = interfaceMethods.iterator(); iter.hasNext();) {
           MetaMethod aMethod = (MetaMethod) iter.next();
           if (method.isSame(aMethod)) {
               method.setInterfaceClass(aMethod.getCallClass());
               return true;
           }
       }
       // it's no interface method, so try to find the highest class
       // in hierarchy defining this method
       Class declaringClass = method.getCallClass();
       for (Class clazz=declaringClass; clazz!=null; clazz=clazz.getSuperclass()) {
           try {
               final Class klazz = clazz;
               final String mName = method.getName();
               final Class[] parms = method.getParameterTypes();
               try {
                   Method m = (Method) AccessController.doPrivileged(new PrivilegedExceptionAction() {
                       public Object run() throws NoSuchMethodException {
                           return klazz.getDeclaredMethod(mName, parms);
                       }
                   });
                   if (!Modifier.isPublic(clazz.getModifiers())) continue;
                   if (!Modifier.isPublic(m.getModifiers())) continue;
                   declaringClass = clazz;
               } catch (PrivilegedActionException pae) {
                   if (pae.getException() instanceof NoSuchMethodException) {
                       throw (NoSuchMethodException) pae.getException();
                   } else {
                       throw new RuntimeException(pae.getException());
                   }
               }
           } catch (SecurityException e) {
               continue;
           } catch (NoSuchMethodException e) {
               continue;
           }
       }
       if (!Modifier.isPublic(declaringClass.getModifiers())) return false;
       method.setCallClass(declaringClass);

       return true;
   }

   private void generateReflector() {
       reflector = registry.loadReflector(theClass, allMethods);
       if (reflector == null) {
           throw new RuntimeException("Should have a reflector for "+theClass.getName());
       }
       // lets set the reflector on all the methods
       for (Iterator iter = allMethods.iterator(); iter.hasNext();) {
           MetaMethod metaMethod = (MetaMethod) iter.next();
           metaMethod.setReflector(reflector);
       }
   }

   public List getMethods() {
       return allMethods;
   }

   public List getMetaMethods() {
       return new ArrayList(newGroovyMethodsList);
   }

   private synchronized List getInterfaceMethods() {
       if (interfaceMethods == null) {
           interfaceMethods = new ArrayList();
           Class type = theClass;
           while (type != null) {
               Class[] interfaces = type.getInterfaces();
               for (int i = 0; i < interfaces.length; i++) {
                   Class iface = interfaces[i];
                   Method[] methods = iface.getMethods();
                   addInterfaceMethods(interfaceMethods, methods);
               }
               type = type.getSuperclass();
           }
       }
       return interfaceMethods;
   }

   private void addInterfaceMethods(List list, Method[] methods) {
       for (int i = 0; i < methods.length; i++) {
           list.add(createMetaMethod(methods[i]));
       }
   }
   
   private static class MethodIndexAction {
       public void iterate(Map classMethodIndex){
           for (Iterator iter = classMethodIndex.entrySet().iterator(); iter.hasNext();) {
               Map.Entry classEntry = (Map.Entry) iter.next();
               Map methodIndex = (Map) classEntry.getValue();
               Class clazz = (Class) classEntry.getKey();
               if (skipClass(clazz)) continue;               
               for (Iterator iterator = methodIndex.entrySet().iterator(); iterator.hasNext();) {
                   Map.Entry nameEntry = (Map.Entry) iterator.next();
                   String name = (String) nameEntry.getKey();
                   List oldList = (List) nameEntry.getValue();
                   List newList = methodNameAction(clazz, name, oldList);
                   if (replaceMethodList()) nameEntry.setValue(newList); 
               }
           }
       }
       public List methodNameAction(Class clazz, String methodName, List methods) {
           List newList = new ArrayList(methods.size());
           for (Iterator methodIter = methods.iterator(); methodIter.hasNext();) {
               MetaMethod method = (MetaMethod) methodIter.next();
               methodListAction(clazz,methodName,method,methods,newList);
           }
           return newList;
       }
       public boolean skipClass(Class clazz) {return false;}
       public void methodListAction(Class clazz, String methodName, MetaMethod method, List oldList, List newList) {}
       public boolean replaceMethodList(){return true;}
   }

   /**
    * @deprecated
    */
   public Object getProperty(Object object, String property) {
       return getProperty(theClass,object,property,false,false);
   }
   
   /**
    * @deprecated
    */
   public void setProperty(Object object, String property, Object newValue) {
       setProperty(theClass,object,property,newValue,false,false);
   }
   
   /**
    * @deprecated
    */
   public Object getAttribute(Object object, String attribute) {
       return getAttribute(theClass,object,attribute,false,false);
   }
   
   /**
    * @deprecated
    */
   public void setAttribute(Object object, String attribute, Object newValue) {
       setAttribute(theClass,object,attribute,newValue,false,false);
   }

   public MetaMethod pickMethod(String methodName, Class[] arguments) {
       return getMethodWithoutCaching(theClass,methodName,arguments,false);
   }
   
   /**
    * @deprecated use pickMethod instead
    */
   protected MetaMethod retrieveMethod(String methodName, Class[] arguments) {
       return pickMethod(methodName,arguments);
   }
   
   /**
    * remove all method call cache entries. This should be done if a 
    * method is added during runtime, but not by using a category.
    */
   protected void clearInvocationCaches() {
       staticMethodCache.clear();
       methodCache.clear();
   }
}