pan class="key">def</span> <span class="nam">_update_loss</span><span class="op">(</span><span class="nam">self</span><span class="op">,</span> <span class="nam">pred</span><span class="op">,</span> <span class="nam">gt</span><span class="op">)</span><span class="op">:</span>&nbsp;</span><span class="r"></span></p>
    <p class="run"><span class="n"><a id="t26" href="#t26">26</a></span><span class="t">        <span class="nam">loss</span> <span class="op">=</span> <span class="nam">self</span><span class="o