code: func MustCreateSampledTimer(base tally.Timer, rate float64) tally.Timer {
  	t, err := NewSampledTimer(base, rate)
  	if err != nil {
  		panic(err)
  	}
  	return t
  }
docs: // MustCreateSampledTimer creates a new sampled timer, and panics if an error
  // is encountered.