span class="o">=</span> <span class="n">functional</span><span class="o">.</span><span class="n">variadic_to_padded</span><span class="p">(</span><span class="nb">input</span><span class="p">,</span> <span class="n">graph</span><span class="o">.</span><span class="n">num_residues</span><span class="p">,</span> <span class="n">value</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">padding_id</span><span class="p">)[</span><span class="mi">0</span><span class="