PROXY-20: Implement A SwitchInterceptor

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/proxy/branches/version-2.0-work@1507684 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/core/src/main/java/org/apache/commons/proxy2/interceptor/SwitchInterceptor.java b/core/src/main/java/org/apache/commons/proxy2/interceptor/SwitchInterceptor.java
index ec4f4de..56b463d 100644
--- a/core/src/main/java/org/apache/commons/proxy2/interceptor/SwitchInterceptor.java
+++ b/core/src/main/java/org/apache/commons/proxy2/interceptor/SwitchInterceptor.java
@@ -82,7 +82,7 @@
 // Inner Classes
 //----------------------------------------------------------------------------------------------------------------------
 
-    private static class Case implements Serializable
+    private static final class Case implements Serializable
     {
         private InvocationMatcher matcher;
         private Interceptor interceptor;