code: @Override
      public final RESTResponse invoke() {
          Utils.require(m_request.getContentLength() > 0, "An input entity is required for this command");
          UNode inNode = UNode.parse(m_request.getInputBody(), m_request.getInputContentType());
          return invokeUNodeIn(inNode);
      }
docs: Declared "final" so subclass does not attempt to override.