And how do I add it to my simple_transform?
# Transforms
    simple_transform = transforms.Compose(
        [
            transforms.ToTensor(),
            transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
        ]
    )

    # Dataset
    train_dataset = datasets.ImageFolder('data/train/', simple_transform)
    valid_dataset = datasets.ImageFolder('data/valid/', simple_transform)