<svg xmlns="http://www.w3.org/2000/svg"
  xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 200 600">
  <!-- 1. patternUnits -->
  <defs>
    <pattern id="patternUnits" width="80" height="80"
      patternUnits="userSpaceOnUse">
      <rect width="50" height="50" fill="blue"/>
      <rect x="50" width="50" height="50" fill="red"/>
      <rect y="50" width="50" height="50" fill="red"/>
      <rect x="50" y="50" width="50" height="50" fill="blue"/>
    </pattern>
  </defs>
  <rect width="100" height="100" stroke="black" fill="url(#patternUnits)"/>
  <g transform="translate(100)">
    <rect width="100" height="100" stroke="black" fill="url(#patternUnits)"/>
  </g>
  <!-- 2. patternContentUnits -->
  <defs>
    <pattern id="patternContentUnits" width="1" height="1"
      patternContentUnits="objectBoundingBox">
      <rect width="0.5" height="0.5" fill="blue"/>
      <rect x="0.5" width="0.5" height="0.5" fill="red"/>
      <rect y="0.5" width="0.5" height="0.5" fill="red"/>
      <rect x="0.5" y="0.5" width="0.5" height="0.5" fill="blue"/>
    </pattern>
  </defs>
  <g transform="translate(0 100)">
    <rect width="100" height="100" stroke="black"
      fill="url(#patternContentUnits)"/>
    <g transform="translate(100)">
      <rect width="100" height="100" stroke="black"
        fill="url(#patternContentUnits)"/>
    </g>
  </g>
  <!-- 3. patternTransform -->
  <defs>
    <pattern id="patternTransform" width="1" height="1"
      patternTransform="rotate(45 50 50)">
      <rect width="50" height="50" fill="blue"/>
      <rect x="50" width="50" height="50" fill="red"/>
      <rect y="50" width="50" height="50" fill="red"/>
      <rect x="50" y="50" width="50" height="50" fill="blue"/>
    </pattern>
  </defs>
  <g transform="translate(0 200)">
    <rect width="100" height="100" stroke="black"
      fill="url(#patternTransform)"/>
    <g transform="translate(100)">
      <rect width="100" height="100" stroke="black"
        fill="url(#patternTransform)"/>
    </g>
  </g>
  <!-- 4. preserveAspectRatio -->
  <defs>
    <pattern id="par" width="1" height="1" viewBox="0.1 0.1 0.6 0.85"
      preserveAspectRatio="none">
      <rect width="50" height="50" fill="blue"/>
      <rect x="50" width="50" height="50" fill="red"/>
      <rect y="50" width="50" height="50" fill="red"/>
      <rect x="50" y="50" width="50" height="50" fill="blue"/>
    </pattern>
  </defs>
  <g transform="translate(0 300)">
    <rect width="100" height="100" stroke="black" fill="url(#par)"/>
    <g transform="translate(100)">
      <rect width="100" height="100" stroke="black" fill="url(#par)"/>
    </g>
  </g>
  <!-- 5. viewBox -->
  <defs>
    <pattern id="viewBox" width="1" height="1" viewBox="0.1 0.1 0.6 0.85"
      preserveAspectRatio="none">
      <rect width="50" height="50" fill="blue"/>
      <rect x="50" width="50" height="50" fill="red"/>
      <rect y="50" width="50" height="50" fill="red"/>
      <rect x="50" y="50" width="50" height="50" fill="blue"/>
    </pattern>
  </defs>
  <g transform="translate(0 400)">
    <rect width="100" height="100" stroke="black" fill="url(#viewBox)"/>
    <g transform="translate(100)">
      <rect width="100" height="100" stroke="black" fill="url(#viewBox)"/>
    </g>
  </g>
  <!-- 6. xlink:href -->
  <defs>
    <pattern id="xlink" xlink:href="#xlinkRef"/>
    <pattern id="xlinkRef" width="1" height="1">
      <rect width="50" height="50" fill="blue"/>
      <rect x="50" width="50" height="50" fill="red"/>
      <rect y="50" width="50" height="50" fill="red"/>
      <rect x="50" y="50" width="50" height="50" fill="blue"/>
    </pattern>
  </defs>
  <g transform="translate(0 500)">
    <rect width="100" height="100" stroke="black" fill="url(#xlink)"/>
    <g transform="translate(100)">
      <rect width="100" height="100" stroke="black" fill="url(#xlink)"/>
    </g>
  </g>
  <!-- If adding more tests here, be sure to update the viewBox on the root svg
       element -->
</svg>