code: def on_disconnect(self, broker):
          
          LOG.debug('%r.on_disconnect()', self)
          if self.receive_side:
              broker.stop_receive(self)
              self.receive_side.close()
          if self.transmit_side:
              broker._stop_transmit(self)
              self.transmit_side.close()
          fire(self, 'disconnect')
docs: Called by :class:`Broker` to force disconnect the stream. The base
          implementation simply closes :attr:`receive_side` and
          :attr:`transmit_side` and unregisters the stream from the broker.