pub trait IsSubclassableExt: IsClass + ParentClassIs {
fn parent_class_init<T: ObjectSubclass>(class: &mut Class<Self>)
where
Self::Parent: IsSubclassable<T>;
fn parent_instance_init<T: ObjectSubclass>(
instance: &mut InitializingObject<T>
)
where
Self::Parent: IsSubclassable<T>;
}