Creating composite rosjava messages without a Node

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I saw that rosjava changed some months ago to define Messages as interfaces rather than instantiable classes (http://answers.ros.org/question/31399/how-do-you-construct-composite-messages-in-rosjava/). I also saw that a Node instance is now required to provide a MessageFactory so that Messages can be created (http://answers.ros.org/question/36044/declare-a-message-outside-of-a-node-scope-problems/).

I'm currently writing material for a university course in which rosjava is used. Last year the students' code to create composite messages was fairly simple, as I supplied them with an Abstract helper class and they only needed to implement methods such as:

public Twist turnLeft() {
  Twist left = new Twist();
  left.angular.z = 0.5;
  return left;
}

However, with the recent changes they now have the triple confusion of a) having to pre-define and populate a Vector3 message to be inserted into the Twist, b) create the Vector3 and a Twist message using a MessageFactory, and c) instantiate a temporary DefaultNode to get access to a MessageFactory. So the code looks like this:

public Twist turnLeft() {
  DefaultNode node = new DefaultNode(null, null, null);
  Twist left = node.getTopicMessageFactory().newFromType(Twist._TYPE);
  Vector3 move = node.getTopicMessageFactory().newFromType(Vector3._TYPE);
  move.setZ(0.5);
  left.setAngular(move);
  return left;
}

Is all the above really necessary, or have I misunderstood the way in which the MessageFactory and composite messages should work? Is there an easier / less verbose way of creating composite messages, particularly when no Node object is already present within the class?