code: func (i *Interceptor) Dialer(f func(string, time.Duration) (net.Conn, error)) func(string, time.Duration) (net.Conn, error) {
  	return func(addr string, timeout time.Duration) (net.Conn, error) {
  		i.monitoring.dialer.WithLabelValues(addr).Inc()
  		return f(addr, timeout)
  	}
  }
docs: // Dialer ...