and `y` is the same</span>
<span class="sd">        sequence shifted by one position to the right.</span>

<span class="sd">        Parameters</span>
<span class="sd">        ----------</span>
<span class="sd">        idx : int</span>
<span class="sd">            Index of the molecule to return.</span>

<span class="sd">        Returns</span>
<span class="sd">        -------</span>
<span class="sd">        Tuple[torch.Tensor, torch.Tensor]</span>
<span class="sd">            A tuple of `(X, y)` where `X` an