private boolean isKnownImmutableClass(ClassNode fieldType, List<String> knownImmutableClasses) {
   if (!fieldType.isResolved()) return false;
   return fieldType.isEnum()
       || ClassHelper.isPrimitiveType(fieldType)
       || fieldType.getAnnotations(MY_TYPE).size() != 0
       || inImmutableList(fieldType.getName())
       || knownImmutableClasses.contains(fieldType.getName());
 }
 public ClassNode getPlainNodeReference() {
   if (ClassHelper.isPrimitiveType(this)) return this;
   ClassNode n = new ClassNode(name, modifiers, superClass, null, null);
   n.isPrimaryNode = false;
   n.setRedirect(redirect());
   if (isArray()) {
     n.componentType = redirect().getComponentType();
   }
   return n;
 }