'Called by BlockingChannel instances to request a call to their
_dispatch_events method or to terminate `process_data_events`;
BlockingConnection will honor these requests from a safe context.
:param int channel_number: positive channel number to request a call
to the channel\'s `_dispatch_events`; a negative channel number to
request termination of `process_data_events`'

def _request_channel_dispatch(self, channel_number):

    self._channels_pending_dispatch.add(channel_number)
