'Assert that useless filter combinations are avoided.
In effective mode, the following filter combinations are useless, since
they would always return an empty list of role assignments:
- group id, since no group assignment is returned in effective mode;
- domain id and inherited, since no domain inherited assignment is
returned in effective mode.'

def _assert_effective_filters(self, inherited, group, domain):

    if group:
        msg = _('Combining    effective    and    group    filter    will    always    result    in    an    empty    list.')
        raise exception.ValidationError(msg)
    if (inherited and domain):
        msg = _('Combining    effective,    domain    and    inherited    filters    will    always    result    in    an    empty    list.')
        raise exception.ValidationError(msg)
