n class="ow">in</span> <span class="bp">self</span><span class="o">.</span><span class="n">coordinates</span><span class="p">:</span>
            <span class="bp">self</span><span class="o">.</span><span class="n">coordinates</span><span class="p">[</span><span class="n">vertex</span><span class="p">]</span> <span class="o">=</span> <span class="p">(</span><span class="n">x</span><span class="p">,</span> <span class="n">y</span><span class="p">)</span>
        <span class="k">else</span><span class="p">:</s