[gdome]Gdome inheritance implementation

[Paolo Casarini <casarini CS UniBO IT>]

It's time to make this question:
In gdome2 there's a different OO implementation regarding gtk one.
It seems to have a particular way to make the methods inheritance using
virtual tables, but it seems to have not an inheritance for data fields.
For example, Why Gdome_xml_Element have its own xmlNode pointer and its
one refcnt int? It shouldn't use the fields in Gdome_xml_Node?

Does anyone have some documentations dealing with the choices that have
produced the gdome2 OO implementation? or dealing with ref, unref,
query_interface methods? 

thanx
Paolo