a based on documentation example</span>
 <span class="n">targets_df</span> <span class="o">=</span> <span class="n">pd</span><span class="o">.</span><span class="n">DataFrame</span><span class="p">({</span>
     <span class="s1">&#39;asset_class&#39;</span><span class="p">:</span> <span class="p">[</span><span class="s1">&#39;STOCK_A&#39;</span><span class="p">,</span> <span class="s1">&#39;STOCK_B&#39;</span><span class="p">,</span> <span class="s1">&#39;CASH&#39;</span><span class="p">],</span>
     <span