n class="o">=</span> <span class="n">tf</span><span class="o">.</span><span class="n">zeros_like</span><span class="p">(</span><span class="n">x</span><span class="p">)</span>
    <span class="n">adv_x</span> <span class="o">=</span> <span class="n">x</span>

    <span class="c1"># Fix labels to the first model predictions for loss computation</span>
    <span class="n">y</span><span class="p">,</span> <span class="n">_nb_classes</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.<