="k">except</span> <span class="n">NonUnitaryState</span> <span class="k">as</span> <span class="n">nUErr</span><span class="p">:</span>
            <span class="k">raise</span> <span class="n">nUErr</span>
        <span class="c1"># print(&quot;\t\tBefore calling buildStochasticOperator&quot;)</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">_operator</span><span class="o">.</span><span class="n">buildStochasticOperator</span><span class="p">(</span>
            <span clas