def forward(self, x):
        """
        Args:
            x (torch.Tensor): input tensor with shape (B, C, H, W).

        Returns:
            torch.Tensor: output tensor with shape (B, C, H, W).
        """

        x = self.act(self.norm1(self.fc1(x)))
        x = self.drop(x)
        x = self.norm2(self.fc2(x))
        x = self.drop(x)
        return x

        Args:
            x (torch.Tensor): input tensor with shape (B, C, H, W).

        Returns:
            torch.Tensor: output tensor with shape (B, C, H, W).
        
mmpretrain/models/backbones/efficientformer.py