code: public PostPersist<Entity<T>> getOrCreatePostPersist()
     {
        Node node = childNode.getOrCreate("post-persist");
        PostPersist<Entity<T>> postPersist = new PostPersistImpl<Entity<T>>(this, "post-persist", childNode, node);
        return postPersist;
     }
docs: If not already created, a new <code>post-persist</code> element with the given value will be created.
  Otherwise, the existing <code>post-persist</code> element will be returned.
  @return  a new or existing instance of <code>PostPersist<Entity<T>></code>