pub trait ContainerImplExt: ObjectSubclass {
fn parent_add(&self, widget: &Widget);
fn parent_remove(&self, widget: &Widget);
fn parent_check_resize(&self);
fn parent_set_focus_child(&self, widget: Option<&Widget>);
fn parent_child_type(&self) -> Type;
fn parent_path_for_child(&self, widget: &Widget) -> WidgetPath;
fn parent_forall(&self, include_internals: bool, callback: &Callback);
}