code: @SuppressWarnings("unchecked")
      public <T extends JCTree> T translate(T tree) {
          if (tree == null) {
              return null;
          } else {
              tree.accept(this);
              JCTree tmpResult = this.result;
              this.result = null;
              return (T)tmpResult; // XXX cast
          }
      }
docs: Visitor method: Translate a single node.