@Override
  public KeySelector<RowData, ShuffleKey> generateKeySelector() {
    return new PrimaryKeySelector();
  }
After the primary key value hash is modulated based on concurrency, the row is routed to
different subtask write

<p>
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/shuffle/RoundRobinShuffleRulePolicy.java