'Get a group by name.
:param str group_name: group name.
:param str domain_id: domain ID.
:returns: group info. See group schema in
:class:`~.IdentityDriverBase`.
:rtype: dict
:raises keystone.exception.GroupNotFound: If the group doesn\'t exist.'

@abc.abstractmethod
def get_group_by_name(self, group_name, domain_id):

    raise exception.NotImplemented()
