code: public static <T> ThriftListenableFuture<T> successfulListenableFuture(T value) {
          final ThriftListenableFuture<T> future = new ThriftListenableFuture<>();
          future.onComplete(value);
          return future;
      }
docs: Returns a new {@link ThriftListenableFuture} instance that has its value set immediately.