def _stop_scheduling_tasks(self):
self._task_socket.close()<EOL>self._task_socket = None<EOL>msg = "<STR_LIT>" +"<STR_LIT>"<EOL>if self.outstanding:<EOL><INDENT>msg += "<STR_LIT>" +"<STR_LIT>"<EOL><DEDENT>warnings.warn(msg, RuntimeWarning)<EOL>
Stop scheduling tasks because an engine has been unregistered
        from a pure ZMQ scheduler.