@Override
 public void mapAtoB(DeviceDO deviceDO, Device device, MappingContext context) {
   Map<String, String> map = Maps.newHashMap();
   if (deviceDO.getDeviceExts() != null) {
     for (DeviceExtDO deviceExtDO : deviceDO.getDeviceExts()) {
       map.put(deviceExtDO.getEntityField().getCode(), deviceExtDO.getValue());
     }
   }
   device.setExtendedAttributes(map);
 }
 @Override
 public void mapBtoA(Device device, DeviceDO deviceDO, MappingContext context) {
   deviceDO.setExtAttributes(device.getExtendedAttributes());
 }