code: func (c *channel) resetDeleteTimer(newDuration time.Duration) {
  	a := c.activity
  	if a.timer == nil {
  		a.timer = time.AfterFunc(newDuration, func() {
  			c.stan.sendDeleteChannelRequest(c)
  		})
  	} else {
  		a.timer.Reset(newDuration)
  	}
  	if c.stan.debug {
  		c.stan.log.Debugf("Channel %q delete timer set to fire in %v", c.name, newDuration)
  	}
  	a.timerSet = true
  }
docs: // Resets the delete timer to the given duration.
  // If the timer was not created, this call will create it.
  // The channelStore's mutex must be held on entry.