How to add group outline? Apply <Paint/> with borderWidth to group?

[voxlz]

I want to have a continous outline accross two shapes that overlap. How can you achive this?

     <Group
        color="green"
     >
        <Circle
           r={20}
           cx={checkpoint.point.x}
           cy={checkpoint.point.y + totalHeight}
        >
           <Paint color="red" strokeWidth={4} style="stroke" />
        </Circle>
        <Rect
           x={checkpoint.point.x - 10}
           y={checkpoint.point.y + totalHeight - 50}
           width={20}
           height={100}
        >
           <Paint color="red" strokeWidth={4} style="stroke" />
        </Rect>
     </Group>

This code creates 2 objects with outlines and puts them on top of each other. I need a way to "flatten" these two shapes and draw an ouline around the union shape. Any ideas how I could achive this?