pub fn expand<M>(collapsed: Node<M>, expanded: Node<M>) -> Node<M>Expand description
collapsed, or expanded once the pointer rests on this node, fading between them like a
hover. Unlike hover, it’s only as big as what it shows, so the item grows to make room
and the island springs along, and it reacts to the pointer over it, not the whole item: a
workspace that shows every window when you point at it.