code: func NewProcessReporter(
  	scope tally.Scope,
  	reportInterval time.Duration,
  ) Reporter {
  	r := new(processReporter)
  	r.init(reportInterval, r.metrics.report)
  
  	processScope := scope.SubScope("process")
  	r.metrics.NumFDs = processScope.Gauge("num-fds")
  	r.metrics.NumFDErrors = processScope.Counter("num-fd-errors")
  	r.metrics.pid = os.Getpid()
  
  	return r
  }
docs: // NewProcessReporter returns a new reporter that reports process
  // metrics, currently just the process file descriptor count.