code: func NewDropsondeMarshaller(logger *gosteno.Logger) *DropsondeMarshaller {
  	messageCounts := make(map[events.Envelope_EventType]*uint64)
  	for key := range events.Envelope_EventType_name {
  		var count uint64
  		messageCounts[events.Envelope_EventType(key)] = &count
  	}
  	return &DropsondeMarshaller{
  		logger:        logger,
  		messageCounts: messageCounts,
  	}
  }
docs: // NewDropsondeMarshaller instantiates a DropsondeMarshaller and logs to the
  // provided logger.