'For internal use only (e.g., Connection needs to remove closed
channels from its channel container). Pass a callback function that will
be called when the channel is being cleaned up after all channel-close
callbacks callbacks.
:param callable callback: The callback to call, having the
signature: callback(channel)'

def _add_on_cleanup_callback(self, callback):

    self.callbacks.add(self.channel_number, self._ON_CHANNEL_CLEANUP_CB_KEY, callback, one_shot=True, only_caller=self)
