code: func (ms *MetricSender) Counter(name string) CounterChainer {
  	chainer := counterChainer{}
  	chainer.emitter = ms.eventEmitter
  	chainer.envelope = &events.Envelope{
  		Origin:    proto.String(ms.eventEmitter.Origin()),
  		EventType: events.Envelope_CounterEvent.Enum(),
  		CounterEvent: &events.CounterEvent{
  			Name: proto.String(name),
  		},
  	}
  	return chainer
  }
docs: // Counter creates a counter event that can be manipulated via cascading calls
  // and then sent via Increment or Add.