def __init__(self, image_reference, tag=None):
        """
        :param image_reference: str, the reference to this image (usually name)
        :param tag: str, tag of the image, when not specified, "latest" is implied
        """
        self.tag = tag
        self.name = image_reference
        self._metadata = None
        self._id = None
def __init__ ( self , image_reference , tag = None ) : self . tag = tag self . name = image_reference self . _metadata = None self . _id = None
:param image_reference: str, the reference to this image (usually name)
        :param tag: str, tag of the image, when not specified, "latest" is implied