Template Widgets inside another GtkBuilder file

[Victor Aurélio Santos <victoraur santos gmail com>]

How can I do that ?
Just build all together results in this warning:

> (ajami:3475): Gtk-CRITICAL **: Error building template class 'AjamiMainWindow' for an instance of type 
> 'AjamiMainWindow': Invalid object type 'HVMeter' on line 2

I've asked on SO[1] and got only one answer.

I stick at "_get_type" workaround/hack but I didn't like it and I
can't do the same thing in Vala (I've not found how to do the same
thing).

More details can be found on SO question.

So, what I really want to know is what is the best option to
accomplish this in Vala and in C too.

[1]: http://stackoverflow.com/questions/24235937/custom-gtk-widget-with-template-ui

-- 
Victor Aurélio Santos