<!DOCTYPE html>
<html>
<head>
<style>body { color: green; }</style>
<link rel="stylesheet" href='data:text/css,body > span { color: red }' type="text/css"/>
<link rel="stylesheet" href='data:text/css,body > span { color: red }' type="text/css"/>
<script>
// Force cloning of the second linked sheet
document.styleSheets[2].cssRules[0];
</script>
</head>
<body>
<div><span>This text should be green</span></div>
</body>
</html>