code: func Time(name string, tags map[string]string, rate float64) *timer {
  	t := &timer{name: name, tags: tags, rate: rate}
  	t.Start()
  	return t
  }
docs: // Time is a shorthand for TimeInMilliseconds for easy code block instrumentation
  //
  // Usage:
  //   t := metrics.Time("foo.bar", map[string]string{"baz":"qux"}, 1.0)
  //   defer t.Done()
  //   ...
  //   t.SetTags(map[string]string{"foo":"bar"}) // totally optional