def _NonImplementedMethod(self, method_name, rpc_controller, callback):
rpc_controller.SetFailed('<STR_LIT>' % method_name)<EOL>callback(None)<EOL>
The body of all methods in the generated service class.

        Args:
          method_name: Name of the method being executed.
          rpc_controller: RPC controller used to execute this method.
          callback: A callback which will be invoked when the method finishes.