code: func (l *LogSender) SendAppErrorLog(appID, message, sourceType, sourceInstance string) error {
  	metrics.BatchIncrementCounter("logSenderTotalMessagesRead")
  	return l.eventEmitter.Emit(makeLogMessage(appID, message, sourceType, sourceInstance, events.LogMessage_ERR))
  }
docs: // SendAppErrorLog sends a log error message with the given appid and log message
  // with a message type of std err.
  // Returns an error if one occurs while sending the event.