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  <path id="thePath" d="M50 50 L 150 50" />
  <text x="50" y="50">PASS</text>
  <pattern id="pat" patternUnits="userSpaceOnUse" x="0" y="0" width="100" height="100">
  <text>
    <textPath id="theTP" xlink:href="#thePath">FAIL</textPath>
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  </pattern>
  <rect width="200" height="200" fill="url(#pat)" stroke="black" stroke-width="1"/>
  <script><![CDATA[
    function runTest() {
      var tp = document.getElementById("theTP");
      tp.setAttributeNS("http://www.w3.org/1999/xlink","href","#wrongPath");
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</svg>