 class="n">Vertex</span><span class="p">(</span><span class="n">v1</span><span class="p">,</span> <span class="n">v1Label</span><span class="p">)</span>
                <span class="k">if</span> <span class="n">v2</span> <span class="ow">not</span> <span class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">vMap</span><span class="p">:</span>
                    <span class="bp">self</span><span class="o">.</span><span class="n">vMap</span><span class="p">[</span><span cla