Trivial refactoring: Add generic type to avoid warnings
diff --git a/src/main/java/org/codehaus/groovy/control/ClassNodeResolver.java b/src/main/java/org/codehaus/groovy/control/ClassNodeResolver.java
index 05c938b..e5842a8 100644
--- a/src/main/java/org/codehaus/groovy/control/ClassNodeResolver.java
+++ b/src/main/java/org/codehaus/groovy/control/ClassNodeResolver.java
@@ -91,7 +91,7 @@
     }
 
     // Map to store cached classes
-    private final Map<String,ClassNode> cachedClasses = new HashMap();
+    private final Map<String, ClassNode> cachedClasses = new HashMap<>();
     /**
      * Internal helper used to indicate a cache hit for a class that does not exist. 
      * This way further lookups through a slow {@link #findClassNode(String, CompilationUnit)}