def METHOD_NAME(self):
    """
    tests that all devices are working properly ...
    """
    for platform in ocl.platforms:
        for _did, device in enumerate(platform.devices):
            logger.debug("Testing %s/%s", platform, device)
            try:
                meas = _measure_workgroup_size((platform.id, device.id))
            except Exception as err:
                logger.error(err)
            else:
                self.assertEqual(meas, device.max_work_group_size,
                                 "Workgroup size for %s/%s: %s == %s" % (platform, device, meas, device.max_work_group_size))