code: func (h Hook) Fire(e *logrus.Entry) error {
  	dataBytes, err := h.formatter.Format(e)
  	if err != nil {
  		return err
  	}
  	_, err = h.writer.Write(dataBytes)
  	return err
  }
docs: // Fire takes, formats and sends the entry to Logstash.
  // Hook's formatter is used to format the entry into Logstash format
  // and Hook's writer is used to write the formatted entry to the Logstash instance.