def forward_momentum(self, x):
    y = self.backbone_momentum(x).flatten(start_dim=1)
    z = self.projection_head_momentum(y)
    z = z.detach()
    return z
def forward_momentum(self, x):
    y = self.backbone_momentum(x).flatten(start_dim=1)
    z = self.projection_head_momentum(y)
    z = z.detach()
    return z