improved a message for RuntimeExceptions.

git-svn-id: http://anonsvn.jboss.org/repos/javassist/trunk@203 30ef5769-5b8d-40dd-aea6-55b5d6557bb3

src/main/javassist/CtClass.java

 
     void freeze() {}
 
+    /* Note: this method is overridden by CtClassType
+     */
     void checkModify() throws RuntimeException {
         if (isFrozen())
             throw new RuntimeException(getName() + " class is frozen");

src/main/javassist/CtClassType.java

     void freeze() { wasFrozen = true; }
 
     void checkModify() throws RuntimeException {
-        super.checkModify();
+        if (isFrozen()) {
+            String msg = getName() + " class is frozen";
+            if (wasPruned)
+                msg += " and pruned";
+
+            throw new RuntimeException(msg);
+        }
+
         wasChanged = true;
     }
 
         }
     }
 
+    /* See also checkModified()
+     */
     private void checkPruned(String method) {
         if (wasPruned)
             throw new RuntimeException(method + "(): " + getName()