n class="o">=</span><span class="kc">None</span><span
            class="p">,</span> <span class="n">begin_time</span><span class="o">=</span><span
            class="kc">None</span><span class="p">,</span>
                 <span class="n">end_time</span><span class="o">=</span><span class="kc">None</span><span
            class="p">):</span>
        <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">        A basic constructor for an ``EulerTourTree`` object.</span>

<span class="sd">        :para