def pre_logits(self, feats: Tuple[List[torch.Tensor]]) -> torch.Tensor:
        """The process before the final classification head.

        The input ``feats`` is a tuple of tensor, and each tensor is the
        feature of a backbone stage. In ``ConformerHead``, we just obtain the
        feature of the last stage.
        """
        # The ConformerHead doesn't have other module,
        # just return after unpacking.
        return feats[-1]
The process before the final classification head.

        The input ``feats`` is a tuple of tensor, and each tensor is the
        feature of a backbone stage. In ``ConformerHead``, we just obtain the
        feature of the last stage.
        
mmpretrain/models/heads/conformer_head.py