"none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field"><th class="field-name">Parameters :</th><td class="field-body"><ul class="first simple">
<li><strong>callback</strong> &#8212; called whenever a message is posted (past or present)</li>
<li><strong>ignorePast</strong> &#8212; <tt class="docutils literal"><span class="pre">true</span></tt> means ignore previous messages</li>
</ul>
</td>
</tr>
<tr class="field"><th class="field-name">Returns :</th><td class="f