@Override
  public CompletableFuture<Void> stopMaster() {
    return this.<Void> newMasterCaller().priority(HIGH_QOS)
      .action((controller, stub) -> this.<StopMasterRequest, StopMasterResponse, Void> call(
        controller, stub, StopMasterRequest.newBuilder().build(),
        (s, c, req, done) -> s.stopMaster(c, req, done), resp -> null))
      .call();
  }
Get the region info for the passed region name. The region name may be a full region name or
encoded region name. If the region does not found, then it'll throw an UnknownRegionException
wrapped by a {@link CompletableFuture}
@return region info, wrapped by a {@link CompletableFuture}
hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java