LayoutManager.getLayoutChild

Retrieves a [gtk.layout_child.LayoutChild] instance for the [gtk.layout_manager.LayoutManager], creating one if necessary.

The child widget must be a child of the widget using manager.

The [gtk.layout_child.LayoutChild] instance is owned by the [gtk.layout_manager.LayoutManager], and is guaranteed to exist as long as child is a child of the [gtk.widget.Widget] using the given [gtk.layout_manager.LayoutManager].