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chromium/third_party/blink/web_tests/external/wpt/selection/shadow-dom/cross-shadow-boundary-5-ref.html 

<!doctype html>
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<div>innerText1</div>
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<div>innerText2</div>
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<script>
  getSelection().setBaseAndExtent(
    document.body.firstChild,
    3,
    document.body.childNodes[4],
  3);
</script>