tion() {
      myDiagram.startTransaction('detach');
      const coll = new go.Set(/*go.Link*/);
      myDiagram.selection.each((node) => {
        if (!(node instanceof go.Node)) return;
        node.linksConnected.each((link) => {
          if (link.category !== '') return; // ignore comments
          // ignore links to other selected nodes
          if (link.getOtherNode(node).isSelected) return;
          // disconnect this link
          coll.add(link);
        });
      });
      myDiagram.removePart