rootClasses := { RTShape . RTLayout . RTBuilder }.

	groups := rootClasses collect: [ :cls |
		g := RTGroup new.
		elements := (RTEllipse new size: 8; color: Color blue) elementsOn: cls withAllSubclasses.
		g addAll: elements.
		edges := RTEdgeBuilder new
			view: g;
			objects: cls withAllSubclasses from: #superclass.
		RTForceBasedLayout on: elements edges: edges.
		g ].

	v := RTView new.
	groups do: [ :aGroup | v addAll: aGroup ].
	RTHorizontalLineLayout new gapSize: 30; on: groups.

	TRConstraint alignFromBottom: groups.
	v