def forward(self, x, skip=None):
    x = self.up(x)
    if (skip is not None):
        x = torch.cat([x, skip], dim=1)
    x = self.conv1(x)
    x = self.conv2(x)
    return x
def forward(self, x, skip=None):
    x = self.up(x)
    if (skip is not None):
        x = torch.cat([x, skip], dim=1)
    x = self.conv1(x)
    x = self.conv2(x)
    return x