The attached <pattern> is not rendered

[fskpf]

Look into this sample from https://developer.mozilla.org/en-US/docs/Web/SVG/Element/pattern

<svg viewBox="0 0 230 100" xmlns="http://www.w3.org/2000/svg">
  <defs>
    <pattern id="star" viewBox="0,0,10,10" width="10%" height="10%">
      <polygon points="0,0 2,5 0,10 5,8 10,10 8,5 10,0 5,2"/>
    </pattern>
  </defs>

  <circle cx="50"  cy="50" r="50" fill="url(#star)"/>
  <circle cx="180" cy="50" r="40" fill="none" stroke-width="20" stroke="url(#star)"/>
</svg>