der</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
            <span class="c1"># Default vertex order</span>
            <span class="n">vertex_coord_iter</span> <span class="o">=</span> <span class="nb">zip</span><span class="p">(</span><span class="n">vertex_builder</span><span class="p">,</span> <span class="n">layout</span><span class="p">)</span>
        <span class="k">else</span><span class="p">:</span>
            <span class="c1"># Specified vertex order</sp