>,</span> <span class="n">grad_y</span><span class="p">:</span> <span class="n">Tensor</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="n">Tuple</span><span class="p">[</span><span class="n">Tensor</span><span class="p">,</span> <span class="kc">None</span><span class="p">,</span> <span class="kc">None</span><span class="p">]:</span>
        <span class="k">return</span> <span class="n">grad_y</span><span class="p">,</span> <span class="kc">None</span><span class="p">,</span> <span c