n class="n">symbol</span> <span class="o">=</span> <span class="s2">&quot;s&quot;</span>

    <span class="k">def</span> <span class="fm">__new__</span><span class="p">(</span><span class="bp">cls</span><span class="p">,</span> <span class="n">stress_matrix</span><span class="p">):</span>
        <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">        Create a Stress object.  Note that the constructor uses __new__</span>
<span class="sd">        rather than __init__ according to the standard met