n class="o">=</span> <span
            class="kc">None</span>

    <span class="n">T</span> <span class="o">=</span> <span class="n">EulerTourTree</span><span class="p">(</span><span
            class="n">root</span><span class="o">=</span><span class="n">new_root</span><span class="p">)</span>
    <span class="n">T</span><span class="o">.</span><span class="n">first</span> <span class="o">=</span> <span
            class="n">first</span>
    <span class="n">T</span><span class="o">.</span><span class="n">f