code: func (m *StandardMeter) Stop() {
  	m.lock.Lock()
  	stopped := m.stopped
  	m.stopped = true
  	m.lock.Unlock()
  	if !stopped {
  		arbiter.Lock()
  		delete(arbiter.meters, m)
  		arbiter.Unlock()
  	}
  }
docs: // Stop stops the meter, Mark() will be a no-op if you use it after being stopped.