="o">.</span><span class="n">left</span><span
            class="p">:</span>
            <span class="n">node</span><span class="o">.</span><span class="n">left</span> <span
            class="o">=</span> <span class="bp">self</span><span class="o">.</span><span
            class="n">_balance_down</span><span class="p">(</span><span class="n">node</span><span
            class="o">.</span><span class="n">left</span><span class="p">)</span>
            <span class="k">if</span> <span class="n">node</span><sp