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chromium/third_party/blink/web_tests/paint/selection/first_letter/first_letter_2fr.html 

<!doctype html>
<style>p::first-letter { font-size: 200%; color: red; }</style>
<p id="start">  [!(5)#]9abcdefghi</p>
<div id="start2">ABC</div>
<p>(a) bc</p>
<div id="end2">DEF</div>
<p id="end">[!(3)#]789abcd</p>
<script>
const selection = window.getSelection();
const start = document.getElementById('start');
const end = document.getElementById('end');
// Select "^(5) to 78|9"
selection.collapse(start.firstChild, 4);
selection.extend(end.firstChild, 9);
</script>