How to use Entity.xml on Java EE 6, or what is an equivalent

So I'm imitating an example given by my professor in which he uses this:

 Response response = target.path("rest").path("todos")
        .path(todo.getId()).request().accept(MediaType.APPLICATION_XML)
        .put(Entity.xml(todo),Response.class);

And I don't have much knowledge about xml but for the project I've been told to make, in netbeans, with glassfish and Java EE 6, I don't... find anything similar to Entity. To be precise this is what I'm talking about:

http://ift.tt/1HxbVOf

And it seems as it was created for java EE 7 and I thought well maybe there's some way to do the same operation in java EE 6?

And I haven't found a way to do it, so far, for java EE 6.