Go.shape in tooltip

Dear Team,

I wanted to customize tooltip with go.shape when I put below code it is showing like in image but this not expected, how to remove the white background around the shape. We have bought this product and have active license. please help us.

var linktooltip =

				$(go.Shape, "circle",
    { fill: "lightgreen" }),
				$(go.TextBlock,  // bound to node data
				  {font: "bold 8pt sans-serif",alignment: go.Spot.Bottom},
				  new go.Binding("text","influencetype"))


You can see how “ToolTip” is defined at https://gojs.net/latest/extensions/buttons.js.

From that you can see that your “ToolTip” contains a Shape named “Border” that surrounds the content that you are adding to it, due to it being an “Auto” Panel. So you can set something like:

  { "Border.fill": "lightyellow" },
  $(go.Shape, ...