def resumeProducing(self):
        """
        Called when the consumer attached to me runs out of buffer.
        """
        # Go backwards over the list so we can remove indexes from it as we go
        for pageridx in range(len(self.pageProducers)-1, -1, -1):
            pager = self.pageProducers[pageridx]
            pager.sendNextPage()
            if not pager.stillPaging():
                del self.pageProducers[pageridx]
        if not self.pageProducers:
            self.transport.unregisterProducer()

        Called when the consumer attached to me runs out of buffer.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/spread/pb.py