default void finish(
      List<ColumnBuilder> properColumnBuilders, ColumnBuilder passThroughIndexBuilder) {
    // do nothing
  }
This method is called after all data is processed. It is used to finalize the output table and
close resource. All remaining data should be written to the columnBuilders.

@param properColumnBuilders A list of {@link ColumnBuilder} for each column in the output
    table.
@param passThroughIndexBuilder A {@link ColumnBuilder} for pass through columns. Index is
    started from 0 of the whole partition. It will be null if table argument is not declared
    with PASS_THROUGH_COLUMNS.
iotdb-api/udf-api/src/main/java/org/apache/iotdb/udf/api/relational/table/processor/TableFunctionDataProcessor.java