public String getShapeUid(ILeaf ent) {
		final Shape result = getShape(ent);
		if (result != null) {
			String uid = result.getUid();
			if (result.isShielded()) {
				uid = uid + ":h";
			}
			return uid;
		}
		assert result == null;
		if (ent.isGroup()) {
			for (IEntity i : shapeMap.keySet()) {
				if (ent.getCode().equals(i.getCode())) {
					return getShape(i).getUid();
				}
			}
			return Cluster.getSpecialPointId(ent);
		}
		throw new IllegalStateException();
	}