 with an existing trace_id and
  parent_id.</td></tr>
<tr><td valign="top"><a href="#tag-2">tag/2</a></td><td>Add a tag to the span in the process dictionary.</td></tr>
<tr><td valign="top"><a href="#tag-3">tag/3</a></td><td>Add a tag with specific service to the span in the process
  dictionary.</td></tr>
</table>

<h2><a name="functions">Function Details</a></h2>

<h3 class="function"><a name="finish-0">finish/0</a></h3>
<div class="spec">
<p><tt>finish() -&gt; ok</tt><br></p>
</div><p>Finish collection o