tartTransaction('rotate ' + angle.toString());
      const sel = new go.Set(/*go.Node*/);
      sel.add(node);
      const coll = tool.computeEffectiveCollection(sel).toKeySet();
      const bounds = myDiagram.computePartsBounds(coll);
      const center = bounds.center;
      coll.each((n) => {
        n.angle += angle;
        n.location = n.location.copy().subtract(center).rotate(angle).add(center);
      });
      myDiagram.commitTransaction('rotate ' + angle.toString());
    }

    function detachSelec