/div>
<div class="block">Add a new UndoOperation to the current update.</div>
<dl class="notes">
<dt>Parameters:</dt>
<dd><code>op</code> - The new operation to add.</dd>
<dd><code>mergeMode</code> - May be either <a href="#MERGE_MODE_NONE"><code>MERGE_MODE_NONE</code></a>, <a href="#MERGE_MODE_UNIQUE"><code>MERGE_MODE_UNIQUE</code></a>,
                  or <a href="#MERGE_MODE_ANY"><code>MERGE_MODE_ANY</code></a>.</dd>
</dl>
</section>
</li>
<li>
<section class="detail" id="endUpdate()">
<h3>endUpdate</h3