code: func (c *Controller) RemoveNotifier(name string) error {
  	c.mu.Lock()
  	defer c.mu.Unlock()
  	currentNotifier, ok := c.notifiers[name]
  	if !ok {
  		return fmt.Errorf("Unknown notification service %s", name)
  	}
  	currentNotifier.removeSubscription()
  	delete(c.notifiers, name)
  	return nil
  }
docs: // RemoveNotifier is used to stop a notification service.
  // It cancels the event loop listening to the notification provider's update channel