code: func (e *sessionMessages) CloseSessionMessageChannel(channel chan SessionMessage) {
  	e.mutex.Lock()
  	defer e.mutex.Unlock()
  	for channelEntry := range e.channels {
  		if channelEntry.channel == channel {
  			close(channelEntry.channel)
  			delete(e.channels, channelEntry)
  			break
  		}
  	}
  }
docs: // CloseSessionMessageChannel closes and unregisters the supplied event channel from the session.