def _CallMethod(self, srvc, method_descriptor,<EOL>rpc_controller, request, callback):
if method_descriptor.containing_service != self.descriptor:<EOL><INDENT>raise RuntimeError(<EOL>'<STR_LIT>')<EOL><DEDENT>method = getattr(srvc, method_descriptor.name)<EOL>return method(rpc_controller, request, callback)<EOL>
Calls the method described by a given method descriptor.

        Args:
          srvc: Instance of the service for which this method is called.
          method_descriptor: Descriptor that represent the method to call.
          rpc_controller: RPC controller to use for this method's execution.
          request: Request protocol message.
          callback: A callback to invoke after the method has completed.