def send_catch_log_deferred(self, signal, **kwargs):
        """
        Like :meth:`send_catch_log` but supports returning `deferreds`_ from
        signal handlers.

        Returns a Deferred that gets fired once all signal handlers
        deferreds were fired. Send a signal, catch exceptions and log them.

        The keyword arguments are passed to the signal handlers (connected
        through the :meth:`connect` method).

        .. _deferreds: https://twistedmatrix.com/documents/current/core/howto/defer.html
        """
        kwargs.setdefault('sender', self.sender)
        return _signal.send_catch_log_deferred(signal, **kwargs)

        Like :meth:`send_catch_log` but supports returning `deferreds`_ from
        signal handlers.

        Returns a Deferred that gets fired once all signal handlers
        deferreds were fired. Send a signal, catch exceptions and log them.

        The keyword arguments are passed to the signal handlers (connected
        through the :meth:`connect` method).

        .. _deferreds: https://twistedmatrix.com/documents/current/core/howto/defer.html
        
stackoverflow/venv/lib/python3.6/site-packages/scrapy/signalmanager.py