TypeError: object of type 'ClassificationDataLoader' has no len()

Question

I keep getting this error TypeError: object of type 'ClassificationDataLoader' has no len(). Has anybody got any idea what to do with that?

class ClassificationDataLoader:
    def __init__(
        self,
        image_paths,
        targets,
        resize,
        augmentations=None,
        backend="pil",
        channel_first=True,
    ):
        """
        :param image_paths: list of paths to images
        :param targets: numpy array
        :param resize: tuple or None
        :param augmentations: albumentations augmentations
        """
        self.image_paths = image_paths
        self.targets = targets
        self.resize = resize
        self.augmentations = augmentations
        self.backend = backend
        self.channel_first = channel_first
        self.dataset = ClassificationDataset(
            image_paths=self.image_paths,
            targets=self.targets,
            resize=self.resize,
            augmentations=self.augmentations,
            backend=self.backend,
            channel_first=self.channel_first,
        )