code: func (l *LogSender) ScanErrorLogStream(appID, sourceType, sourceInstance string, reader io.Reader) {
  	l.scanLogStream(appID, sourceType, sourceInstance, l.SendAppErrorLog, reader)
  }
docs: // ScanErrorLogStream sends a log error message with the given meta-data for each line from reader.
  // Restarts on read errors and continues until EOF.