@Override
  public CompletableFuture<List<SecurityCapability>> getSecurityCapabilities() {
    return this.<List<SecurityCapability>> newMasterCaller()
      .action((controller, stub) -> this.<SecurityCapabilitiesRequest, SecurityCapabilitiesResponse,
        List<SecurityCapability>> call(controller, stub,
          SecurityCapabilitiesRequest.newBuilder().build(),
          (s, c, req, done) -> s.getSecurityCapabilities(c, req, done),
          (resp) -> ProtobufUtil.toSecurityCapabilityList(resp.getCapabilitiesList())))
      .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