import abc
from collections import namedtuple
from typing import Iterable

ImageMetadataPair = namedtuple("ImageMetadataPair", ["image", "metadata"])


class ImageExtractor(abc.ABC):

    @abc.abstractmethod
    def extract(self, obj) -> Iterable[ImageMetadataPair]:
        """Extracts images from an object"""
        pass

    def __call__(self, obj):
        return self.extract(obj)