'Infers user name and subject urn from self.urn.'

def InferUserAndSubjectFromUrn(self):

    (_, hunts_str, hunt_id, user, _) = self.urn.Split(5)
    if (hunts_str != 'hunts'):
        raise access_control.UnauthorizedAccess(('Approval    object    has    invalid    urn    %s.' % self.urn), requested_access=self.token.requested_access)
    return (user, aff4.ROOT_URN.Add('hunts').Add(hunt_id))
