def save_image(self, image):
        image_id = str(image.identifier)
        metadata = self._from_mongo_meta(self.collection.find_one( { "_id": image_id } ))
        if not metadata:
            raise ImageFactoryException('Image %s not managed, use "add_image()" first.' % image_id)
        self._save_image(image)
TODO: Docstring for save_image
dataset/ETHPy150Open redhat-imaging/imagefactory/imgfac/MongoPersistentImageManager.py/MongoPersistentImageManager.save_image