def pre_logits(self, feats: Tuple[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 ``LinearClsHead``, we just obtain the
        feature of the last stage.
        """
        # The LinearClsHead 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 ``LinearClsHead``, we just obtain the
        feature of the last stage.
        
mmpretrain/models/heads/linear_head.py