chromium/third_party/blink/manual_tests/caret-in-columns.html

<div id="target" style="
    margin: 100px;
    -webkit-columns: 3;
    width: 300px;
    height: 100px;
    -webkit-user-modify: read-write;
    outline: none;
">
    <br>
    <br>
    <br>
    <br>
    <br>
    <br>
    The blinking insertion point should be here &rarr;
</div>
<script>
    var target = document.getElementById("target");
    target.focus();
    getSelection().modify("move", "forward", "documentboundary");
</script>