    def forward(self, x):
        """forward function"""
        # (B, C, H, W) -> (B, C, 1)

        x = nn.functional.adaptive_avg_pool2d(x, 1).flatten(1)
        # Shape : [B, C]
        out = self.cls(x)
        return out
forward function
towhee/models/mpvit/mpvit.py