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 stage_blocks stage. In ``VigClsHead``, we just obtain the
        feature of the last stage.
        """
        feats = feats[-1]
        feats = self.fc1(feats)
        feats = self.bn(feats)
        feats = self.act(feats)
        feats = self.drop(feats)

        return feats
The process before the final classification head.

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