chromium/third_party/blink/web_tests/editing/inserting/5803706-2.html

<div id="description">This tests to make sure that hitting return inside (but not at the end of) a header element clones it. Below there should be two identical h2 elements.</div>
<div id="edit" contentEditable="true"><h2 id="h2">foo</h2></div>

<script>
if (window.testRunner)
    testRunner.dumpAsText();
h2 = document.getElementById("h2");
text = h2.firstChild;
window.getSelection().collapse(text, text.length - 1);
document.execCommand("InsertParagraph");
if (window.testRunner)
    document.body.innerText = document.getElementById("description").innerText + "\n\n" + document.getElementById("edit").innerHTML;
</script>