d `y` are both torch tensors. `X` is a sequence of</span>
<span class="sd">            integers representing the SMILES tokens, and `y` is the same sequence shifted</span>
<span class="sd">            by one position to the right.</span>
<span class="sd">        &quot;&quot;&quot;</span>
        <span class="n">molecule</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">label_encoded_molecules</span><span class="p">[</span><span class="n">idx</span><span clas