Link element returns empty string

[Huy-Ngo]

I'm trying to parse HTML from Wiktionary. Words appearing in <a> tags are not added to the final result. For example:

HTML:

<span class="Latn" lang="en" about="#mwt127" typeof="mw:Transclusion"><a rel="mw:WikiLink" href="/wiki/yet#English" title="yet">yet</a>, <a rel="mw:WikiLink" href="/wiki/not_yet#English" title="not yet">not yet</a></span>

Expected output: yet, not yet
Actual output: ,

[Huy-Ngo]

I have just read the tests and I think they're supposed to return /wiki/yet#English, /wiki/not_yet#English, but it doesn't even return that.