trings with ::before and ::after" class="ex fallback-before-mixed fallback-after-mixed">label</button><br>
<h3 data-alt-text-before="alt-before" data-alt-text-after="alt-after" data-expectedlabel="start alt-before end label start alt-after end" data-testname="heading name from fallback content mixing attr() and strings with ::before and ::after" class="ex fallback-before-mixed fallback-after-mixed">label</h3>
<a href="#" data-alt-text-before="alt-before" data-alt-text-after="alt-after" data-expectedlabel="s