r">Firestore</span>.<span class="constructor">Collection</span>.t&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;unit&nbsp;<span class="constructor">BsAsyncMonad</span>.<span class="constructor">Callback</span>.t<br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">end</span><br>
&nbsp;&nbsp;<span class="keyword">module</span>&nbsp;<span class="constructor">Storage</span>&nbsp;:<br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">sig</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="keyword">type</sp