'Returns the list of group specs for a given group type.'

@wsgi.Controller.api_version('3.11')
def index(self, req, group_type_id):

    context = req.environ['cinder.context']
    self._check_policy(context)
    self._check_type(context, group_type_id)
    return self._get_group_specs(context, group_type_id)
