<!DOCTYPE HTML>
<html>
<body>
  <div style="position:absolute;">Hello</div>
  <div style="position:fixed;">Kitty</div>
  <script>
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    document.documentElement.style.display = "table";
    document.body.offsetTop;
    document.documentElement.style.display = "";
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    document.documentElement.style.position = "absolute";
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    document.documentElement.style.display = "table";
    document.body.offsetTop;
    document.documentElement.style.display = "";
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    document.documentElement.style.position = "fixed";
    document.body.offsetTop;
    document.documentElement.style.display = "table";
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</body>
</html>