code: func NewConntrackCollector() (Collector, error) {
  	return &conntrackCollector{
  		current: prometheus.NewDesc(
  			prometheus.BuildFQName(namespace, "", "nf_conntrack_entries"),
  			"Number of currently allocated flow entries for connection tracking.",
  			nil, nil,
  		),
  		limit: prometheus.NewDesc(
  			prometheus.BuildFQName(namespace, "", "nf_conntrack_entries_limit"),
  			"Maximum size of connection tracking table.",
  			nil, nil,
  		),
  	}, nil
  }
docs: // NewConntrackCollector returns a new Collector exposing conntrack stats.