<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="data:text/css,@-moz-document domain(example.com) {}';">
<link rel="stylesheet" href="data:text/css,@-moz-document domain(example.com) {}';">
<script>
// Force a unique inner for the second linked sheet
document.styleSheets[1].cssRules[0];
</script>
</head>
</html>