def disconnect(self, receiver, signal, **kwargs):
        """
        Disconnect a receiver function from a signal. This has the
        opposite effect of the :meth:`connect` method, and the arguments
        are the same.
        """
        kwargs.setdefault('sender', self.sender)
        return dispatcher.disconnect(receiver, signal, **kwargs)

        Disconnect a receiver function from a signal. This has the
        opposite effect of the :meth:`connect` method, and the arguments
        are the same.
        
stackoverflow/venv/lib/python3.6/site-packages/scrapy/signalmanager.py