SVG
This is also possible using SVG.
The SVG version is very short as it mainly only requires an Arc command to control its shape, size and position.
<svg width="50%" viewbox="0 0 100 50">
<path d="M50,35
a20,20 0 1,0 0,-20
a20,20 0 1,0 0,20z"
fill="white"
stroke="black">
</path>
</svg>
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