code: public OneToMany<Attributes<T>> getOrCreateOneToMany()
     {
        List<Node> nodeList = childNode.get("one-to-many");
        if (nodeList != null &&  nodeList.size() > 0)
        {
           return new OneToManyImpl<Attributes<T>>(this, "one-to-many", childNode, nodeList.get(0));
        }
        return createOneToMany();
     }
docs: If not already created, a new <code>one-to-many</code> element will be created and returned.
  Otherwise, the first existing <code>one-to-many</code> element will be returned.
  @return the instance defined for the element <code>one-to-many</code>