The node will block the background image of the container

When I add a node to a container that has a background image set, the node will obscure the background image of the container. What can I do to make the background image appear in front of the node?

 myDiagram.groupTemplateMap.add("OfGroups",
                $(go.Group, "Auto",
                    {
                        background: "transparent",
                        computesBoundsAfterDrag: true,
                        computesBoundsIncludingLocation: true,
                        handlesDragDropForMembers: true,
                        mouseDrop: finishDrop,
                        layout:
                            $(go.GridLayout,
                                {
                                    wrappingColumn: 3,
                                    alignment: go.GridLayout.Position,
                                    cellSize: new go.Size(1, 1),
                                    spacing: new go.Size(4, 4),
                                    sorting: go.GridLayout.Forward
                                })
                    },
                    new go.Binding("background", "isHighlighted", function (h) {
                        return h ? "rgba(255,0,0,0.2)" : "transparent";
                    }),
                    new go.Binding("location", "loc", go.Point.parse).makeTwoWay(go.Point.stringify),
                    $(go.Shape, "RoundedRectangle",
                        {
                            fill: null,
                            stroke: "#FFDD33",
                            strokeWidth: 2
                        }),
                    $(go.Picture,
                        {
                            width: 46,
                            height: 45,
                            source: "./v-icon.png",
                            alignment: new go.Spot(1, 0, 0, 0),
                            alignmentFocus: go.Spot.TopRight
                        }),
                    $(go.Panel, "Vertical",
                        {
                            minSize: new go.Size(200, 100)
                        },
                        $(go.Placeholder,
                            {
                                padding: 5,
                                alignment: go.Spot.TopLeft
                            })
                    )
                ));

thianks

In your group set the layer to foreground and add a transparent background:

                    layerName: 'Foreground',
                    //background: "transparent",

This is exactly what I want, thank you.