code: func (c *Client) Depart(channel string) {
  	if c.connActive.get() {
  		go c.send(fmt.Sprintf("PART #%s", channel))
  	}
  
  	c.channelsMtx.Lock()
  	delete(c.channels, channel)
  	c.channelUserlistMutex.Lock()
  	delete(c.channelUserlist, channel)
  	c.channelUserlistMutex.Unlock()
  	c.channelsMtx.Unlock()
  }
docs: // Depart leave a twitch channel