@VisibleForTesting
  protected void expireSnapshots(long mustOlderThan, int minCount) {
    if (changeMaintainer != null) {
      changeMaintainer.expireSnapshots(mustOlderThan, minCount);
    }
    baseMaintainer.expireSnapshots(mustOlderThan, minCount);
  }
Table maintainer for mixed-iceberg and mixed-hive tables.
amoro-ams/src/main/java/org/apache/amoro/server/optimizing/maintainer/MixedTableMaintainer.java