Base</code></a>    
</div></div>
</div>
<div class="declaration" id="func-index-before_">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-index-before_">func index(<wbr>before:)</a>
     <span class="required">Required</span>    
<div class="comment collapse" id="comment-func-index-before_"><div class="p">
    <p>Returns the position immediately before the given index.</p>

<p><strong><code>i</code>:</strong>  A valid index of the collection. <code>i</code> must be greater than
  <code>sta