>
<span class="w">  </span><span class="c1">//    |-&gt; B</span>
<span class="w">  </span><span class="c1">// A--|</span>
<span class="w">  </span><span class="c1">//    |-&gt; C</span>
<span class="w">  </span><span class="k">const</span><span class="w"> </span><span class="n">std</span><span class="o">::</span><span class="n">vector</span><span class="o">&lt;</span><span class="n">std</span><span class="o">::</span><span class="n">string</span><span class="o">&gt;</span><span class="w"> </span><span clas