lass="n">a</span><span class="o">.</span><span class="n">matrix</span><span class="o">.</span><span class="n">shape</span><span class="p">)</span><span class="si">}</span><span class="s1"> instead.&#39;</span><span class="p">)</span>

    <span class="k">if</span> <span class="n">chart_types</span> <span class="ow">is</span> <span class="kc">None</span><span class="p">:</span>
        <span class="n">chart_types</span> <span class="o">=</span> <span class="p">[</span><span class="s1">&#39;attention_matrix&#