code: func (st *stateTracker) DelChannel(c string) *Channel {
  	st.mu.Lock()
  	defer st.mu.Unlock()
  	if ch, ok := st.chans[c]; ok {
  		st.delChannel(ch)
  		return ch.Channel()
  	}
  	logging.Warn("Tracker.DelChannel(): %s not tracked.", c)
  	return nil
  }
docs: // Removes a Channel from being tracked.