As a good practice, we disable the learnable scale parameter in the batch normalization layers, because on one hand the following relu + convolutional layers make it redundant (as noted in the documentation). But also because it should be disabled based on theory when using spectral normalization (section 4.1), which is not used here, but is common in GANs. We also disable the bias in the fully connected and convolutional layers, because the following batch normalization makes it redundant.