def is_bias_before_norm(norm_type='instance'):
    """When using BatchNorm, the preceding Conv layer does not use bias,
    but it does if using InstanceNorm.
    """
    if norm_type == 'instance':
        return True
    elif norm_type == 'batch':
        return False
    else:
        raise NotImplementedError(f"Normalization layer `{norm_type}` not supported")