<!DOCTYPE html>
<html>
<body>
<div id="container"></div>
<script src="../../resources/dump-as-markup.js"></script>
<script>

container.innerHTML = `<span contenteditable style="display: block; white-space: pre-line;"></span>`;
container.firstChild.focus();
document.execCommand('insertLineBreak', false, null);
Markup.dump(container);

</script>
</body>
</html>