I recommend using same schema as [SwitchStatisticsMap](https://github.com/dana-i2cat/opennaas/blob/develop/extensions/bundles/openflowswitch.driver.floodlight/src/main/java/org/opennaas/extensions/openflowswitch/driver/floodlight/protocol/portstatisticsclient/wrappers/SwitchStatisticsMap.java). I would be easy adding elements to the map.