code: private void init()
      {
          TreeNode delegateRoot = null;
          if (delegate != null)
          {
              delegateRoot = (TreeNode) delegate.getRoot();
          }
          thisToDelegate.clear();
          delegateToThis.clear();
          if (delegateRoot == null)
          {
              root = null;
              return;
          }
          root = createNode(delegateRoot);
      }
docs: Initialize this tree model