s="identifier">extension</span><span class="special">.</span><span class="identifier">first</span><span class="special">;</span>
            <span class="keyword">if</span><span class="special">(!</span> <span class="identifier">extension</span><span class="special">.</span><span class="identifier">second</span><span class="special">.</span><span class="identifier">empty</span><span class="special">())</span>
                <span class="identifier">os</span> <span class="special">&lt;&lt;</span> <span clas