code: public static <T> ThriftCompletableFuture<T> failedCompletedFuture(Exception e) {
          final ThriftCompletableFuture<T> future = new ThriftCompletableFuture<>();
          future.onError(e);
          return future;
      }
docs: Returns a new {@link ThriftCompletableFuture} instance that has an exception set immediately.