transparent', stroke: 'black', strokeWidth: 1}),
          new go.Panel('Horizontal', {
            row: 0,
            stretch: go.Stretch.Vertical,
            defaultStretch: go.Stretch.Horizontal
          })
            .add(
              makeTabLabel('Rectangles', true),
              makeTabLabel('Triangles'),
              makeTabLabel('Other')
            )
        ),
        new go.Panel('Auto', {row: 2, stretch: go.GraphObject.fill})
          .add(
            new go.Shape({fill: 'white', strok