Revision control
++ <svg>
++ <pattern id="fill-pattern" patternUnits="userSpaceOnUse" width="20" height="20">
++ <rect x="0" y="0" width="10" height="10" fill="red"/>
++ <rect x="10" y="10" width="10" height="10" fill="green"/>
++ </pattern>
++ <pattern id="stroke-pattern" patternUnits="userSpaceOnUse" width="10" height="10">
++ <rect x="0" y="0" width="5" height="5" fill="blue"/>
++ <rect x="5" y="5" width="5" height="5" fill="yellow"/>
++ </pattern>
++ <rect x="0" y="0" width="100" height="100" fill="url(#fill-pattern)" stroke="url(#stroke-pattern)" stroke-width="10"/>
++ </svg>