@Override
  public CompletableFuture<List<SnapshotDescription>> listSnapshots(Pattern pattern) {
    Preconditions.checkNotNull(pattern,
      "pattern is null. If you don't specify a pattern, use listSnapshots() instead");
    return getCompletedSnapshots(pattern);
  }
Compact the region at specific region server.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java