'Get slo and workload settings from a storage group.
:param array: the array serial number
:param sg_name: the storage group name
:returns: storage group slo settings'

def get_slo_workload_settings_from_storage_group(self, array, sg_name):

    slo = 'NONE'
    workload = 'NONE'
    storage_group = self.rest.get_storage_group(array, sg_name)
    if storage_group:
        try:
            slo = storage_group['slo']
            workload = storage_group['workload']
        except KeyError:
            pass
    else:
        exception_message = (_('Could    not    retrieve    storage    group    %(sg_name)%.    ') % {'sg_name': sg_name})
        LOG.error(exception_message)
        raise exception.VolumeBackendAPIException(data=exception_message)
    return ('%(slo)s+%(workload)s' % {'slo': slo, 'workload': workload})
