code: public CompletionStage<Optional<Map<String, CompletionStage<Result<R>>>>> callAsync(
              SaltClient client,
              Target<?> target,
              AuthMethod auth,
              EventStream events,
              CompletionStage<GenericError> cancel,
              Batch batch) {
          return callAsync(client, target, auth, events, cancel, Optional.of(batch));
      }
docs: Calls this salt call via the async client and returns the results
  as they come in via the event stream.
  
  @param client SaltClient instance
  @param target the target for the function
  @param events the event stream to use
  @param cancel future to cancel the action
  @param auth authentication credentials to use
  @param batch parameter for enabling and configuring batching
  @return a map from minion id to future of the result.