pan> <span class="bp">self</span><span class="o">.</span><span class="n">first</span>
        <span class="n">current</span> <span class="o">=</span> <span class="bp">self</span><span
            class="o">.</span><span class="n">first</span><span class="o">.</span><span class="n">suc</span>
        <span class="k">while</span> <span class="n">current</span> <span class="o">!=</span> <span
            class="bp">self</span><span class="o">.</span><span class="n">first</span><span class="p">:</span>
        