n class="n">keys</span><span class="p">())</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">window</span> <span class="o">=</span> <span class="n">window</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">mid_i</span> <span class="o">=</span> <span class="n">window</span> <span class="o">//</span> <span class="mi">2</span>
        
    <span class="k">def</span> <span class="nf">__getitem__</span><span class="p">(</span><span class="bp">self<