code: func NewARPCollector() (Collector, error) {
  	return &arpCollector{
  		entries: prometheus.NewDesc(
  			prometheus.BuildFQName(namespace, "arp", "entries"),
  			"ARP entries by device",
  			[]string{"device"}, nil,
  		),
  	}, nil
  }
docs: // NewARPCollector returns a new Collector exposing ARP stats.