code: @Override
      public java.util.concurrent.Future<SubscribeResult> subscribeAsync(String topicArn, String protocol, String endpoint) {
  
          return subscribeAsync(new SubscribeRequest().withTopicArn(topicArn).withProtocol(protocol).withEndpoint(endpoint));
      }
docs: Simplified method form for invoking the Subscribe operation.
  
  @see #subscribeAsync(SubscribeRequest)