Issue in CycleGan-Pix2Pix while calling Discriminator() about pytorch-gan HOT 2 CLOSED

class Discriminator(nn.Module):
    def __init__(self, in_channels=3):
        super(Discriminator, self).__init__()

        def discriminator_block(in_filters, out_filters, stride, normalize):
            """Returns layers of each discriminator block"""
            layers = [nn.Conv2d(in_filters, out_filters, 3, stride, 1)]
            if normalize:
                layers.append(nn.InstanceNorm2d(out_filters))
            layers.append(nn.LeakyReLU(0.2, inplace=True))
            return layers

        layers = []
        layers.extend(discriminator_block(in_channels, 64, 2, False))
        layers.extend(discriminator_block(64, 128, 2, True))
        layers.extend(discriminator_block(128, 256, 2, True))
        layers.extend(discriminator_block(256, 512 , 2, True))
        layers.append(nn.Conv2d(512, 1, 3, 1, 1))
        self.model = nn.Sequential(*layers)

    def forward(self, img):
        return self.model(img)