@Override
  protected RowData appendMetaColumns(RowData data, Long fileOffset) {
    return new JoinedRowData(data, GenericRowData.of(fileOffset));
  }
task writer for {@link KeyedTable#changeTable()} ()}. Dev should make sure outputFileFactory
write to change table's location
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/write/FlinkChangeTaskWriter.java