'Clone an image.
Note that clone operation is backend-dependent. The backend may ask
the image API for a list of image "locations" and select one or more
of those locations to clone an image from.
:param image_id_or_uri: The ID or URI of an image to clone.
:raises: exception.ImageUnacceptable if it cannot be cloned'

def clone(self, context, image_id_or_uri):

    reason = _('clone()    is    not    implemented')
    raise exception.ImageUnacceptable(image_id=image_id_or_uri, reason=reason)
