n><span class="n">_chance_probabilities</span> <span class="o">==</span> <span class="s2">&quot;must_100%&quot;</span><span class="p">:</span>
            <span class="k">if</span> <span class="nb">sum</span><span class="p">(</span><span class="n">probabilities</span><span class="p">)</span> <span class="o">!=</span> <span class="nb">float</span><span class="p">(</span><span class="mi">1</span><span class="p">):</span>
                <span class="k">raise</span> <span class="ne">ValueError</span><span clas