<span class="o">!=</span> <span class="n">i</span><span class="p">:</span>
                    <span class="n">K_ij</span><span class="p">[</span><span class="n">j</span><span class="p">,</span> <span class="n">i</span><span class="p">]</span> <span class="o">=</span> <span class="n">k_ij</span>

        <span class="c1"># Enforce kernel normalization if requested.</span>
        <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">normalize_kernel</span><span class=