code: func (d *Discovery) watchFiles() {
  	if d.watcher == nil {
  		panic("no watcher configured")
  	}
  	for _, p := range d.paths {
  		if idx := strings.LastIndex(p, "/"); idx > -1 {
  			p = p[:idx]
  		} else {
  			p = "./"
  		}
  		if err := d.watcher.Add(p); err != nil {
  			level.Error(d.logger).Log("msg", "Error adding file watch", "path", p, "err", err)
  		}
  	}
  }
docs: // watchFiles sets watches on all full paths or directories that were configured for
  // this file discovery.