code: func NewDiskstatsCollector() (Collector, error) {
  	return &diskstatsCollector{
  		rxfer:  typedDesc{readsCompletedDesc, prometheus.CounterValue},
  		rbytes: typedDesc{readBytesDesc, prometheus.CounterValue},
  		wxfer:  typedDesc{writesCompletedDesc, prometheus.CounterValue},
  		wbytes: typedDesc{writtenBytesDesc, prometheus.CounterValue},
  		time:   typedDesc{ioTimeSecondsDesc, prometheus.CounterValue},
  	}, nil
  }
docs: // NewDiskstatsCollector returns a new Collector exposing disk device stats.