Broken link on page https://developer.gnome.org/gobject/stable/howto-gobject.html
Read the page to the example of code for classes. Click to the macro "G_BEGIN_DECLS". The result is https://developer.gnome.org/gobject/glib-Miscellaneous-Macros.html#G-BEGIN-DECLS:CAPS
Not Found
The requested URL /gobject/glib-Miscellaneous-Macros.html was not found on this server. Apache/2.2.15 (Red Hat) Server at developer.gnome.org Port 80