agram.nodeTemplate = new go.Node('Spot', {
      selectionAdorned: false,
      locationSpot: go.Spot.Center
    })
      .add(
        new go.Panel('Auto')
          .add(
            new go.Shape('RoundedRectangle', {
              stroke: 'transparent',
              strokeWidth: 3,
              spot1: go.Spot.TopLeft,
              spot2: go.Spot.BottomRight
            })
              .bindObject('stroke', 'isSelected', (s) => (s ? 'dodgerblue' : 'transparent')), // shown when selected
            ne