nested-with-single-empty-block.html

<!DOCTYPE html>
<p>There should be three vertical lines below.</p>
<div style="-webkit-columns:2; -webkit-column-rule:3px solid; -webkit-column-gap:9px; width:227px;">
    <div style="-webkit-columns:2; -webkit-column-rule:3px solid; -webkit-column-gap:9px;">
        <div style="height:200px;"></div>
    </div>
</div>

chromium/third_party/blink/web_tests/fast/multicol/nested-with-single-empty-block.html