

  GTK widget abc_def_ghi becomes Perl widget Gtk::Abc::DefGhi
  
  GTK widget gtk_def_ghi becomes Perl widget Gtk::DefGhi
  
  GDK widget gdk_def_ghi becomes Perl widget Gtk::Gdk::DefGhi
  
  GNOME widget gnome_foo_bar becomes Perl widget Gtk::Gnome::FooBar
  
  GNOME widget gtk_gnome_foo_bar becomes Perl widget Gtk::Gnome::FooBar
  
  
  XS code may refer to PerlGtk objects, along with these variants:
  
     Gtk::FooBar_Sink = sink the object before returning it
     Gtk::Widget_Up = upcast the object to it's real object type
     Gtk::Widget_Sink_Up
     Gtk::Widget_OrNULL = accept undef as a zero ptr
     
     