any interface vtable for the interface, or the default vtable for the interface
a pointer to an array of pointers to GParamSpec structures. The paramspecs are owned by GLib, but the array should be freed with g_free() when you are done with it. [array length=n_properties_p][transfer container]
Lists the properties of an interface.Generally, the interface vtable passed in as g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek(). Since 2.4