def METHOD_NAME():
    normalizer = normalization.Normalizer.from_config(
        config=normalization.PreprocessingConfig(
            ensure_rgb=False, ensure_grayscale=False, imagenet_mode=None
        )
    )
    assert normalizer.image_key == "image"
    assert normalizer.ensure_float == True
    assert normalizer.ensure_rgb == False
    assert normalizer.ensure_grayscale == False
    assert normalizer.imagenet_mode is None
    normalizer = normalization.Normalizer.from_config(
        config=normalization.PreprocessingConfig(
            ensure_rgb=False, ensure_grayscale=False, imagenet_mode="tf"
        )
    )
    assert normalizer.image_key == "image"
    assert normalizer.ensure_float == True
    assert normalizer.ensure_rgb == False
    assert normalizer.ensure_grayscale == False
    assert normalizer.imagenet_mode is "tf"