Method collapse

src/main/java/fieldbox/boxes/plugins/BoxGroup.java:189–210

()

	Map<String, Boolean> collapsedState = new LinkedHashMap<>();

	private void collapse() {

//		if (this.parents().size()==0)
//		{
			Box root = this.find(Boxes.root, both())
				.findFirst()
				.get();
			root.connect(this);
//		}

		this.properties.put(_collapsed, true);
		collapsedAt = this.properties.get(Box.frame);
		collapsed = true;
//		this.breadthFirst(this.downwards())
		this.children().stream()
			.filter(x -> x != this)
			.forEach(x -> {
				collapsedState.put(x.properties.getOrConstruct(IO.id), x.disconnected);
				x.disconnected = true;
			});
		Drawing.dirty(this, 2);
	}

	private void expand() {
		this.properties.put(_collapsed, false);