 The implementation of the sink stays pretty much
          the same as before. Now we have to define the factory:
        </p>
<p>
</p>
<pre class="programlisting"><span class="comment">// Factory for the stat_collector sink</span>
<span class="keyword">class</span> <span class="identifier">stat_collector_factory</span> <span class="special">:</span>
    <span class="keyword">public</span> <span class="identifier">logging</span><span class="special">::</span><span class="identifier">sink_factory</span><spa