private CompletableFuture<List<SnapshotDescription>> getCompletedSnapshots(Pattern pattern) {
    return this.<List<SnapshotDescription>> newMasterCaller()
      .action((controller, stub) -> this.<GetCompletedSnapshotsRequest,
        GetCompletedSnapshotsResponse, List<SnapshotDescription>> call(controller, stub,
          GetCompletedSnapshotsRequest.newBuilder().build(),
          (s, c, req, done) -> s.getCompletedSnapshots(c, req, done),
          resp -> ProtobufUtil.toSnapshotDescriptionList(resp, pattern)))
      .call();
  }
Compact the region at specific region server.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java