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

        Returns:
            torch.Tensor: output tensor with shape (B, N, C).
        """
        x = self.drop1(self.act(self.fc1(x)))
        x = self.drop2(self.fc2(x))
        return x

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

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