public static SeriesPartitionExecutor getSeriesPartitionExecutor(
      String executorName, int seriesPartitionSlotNum) {
    if (EXECUTOR == null) {
      initStaticSeriesPartitionExecutor(executorName, seriesPartitionSlotNum);
    }
    return EXECUTOR;
  }
All SeriesPartitionExecutors must be subclasses of SeriesPartitionExecutor
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/partition/executor/SeriesPartitionExecutor.java