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