"ex">
    link2
    <img id="nested_image_label2" alt="image" src="data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==">
    <!-- image skipped in this link (when computing heading text) because it was already referenced by the first link within this heading label recursion cycle. -->
    <!-- but image not skipped when computing the text of the link itself since it has not been referenced in that context -->
    link3
  </a>
</h3>


<!-- Note: The following test is out of lin