@Override
  public CompletableFuture<RegionLocations> getMetaRegionLocations() {
    return tracedFuture(
      () -> this
        .<GetMetaRegionLocationsResponse> call(
          (c, s, d) -> s.getMetaRegionLocations(c,
            GetMetaRegionLocationsRequest.getDefaultInstance(), d),
          r -> r.getMetaLocationsCount() != 0, "getMetaLocationsCount")
        .thenApply(AbstractRpcBasedConnectionRegistry::transformMetaRegionLocations),
      getClass().getSimpleName() + ".getMetaRegionLocations");
  }
Simple helper to transform the result of getMetaRegionLocations() rpc.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/AbstractRpcBasedConnectionRegistry.java