this.positionStore = positionStore;
deviceStore.addStoreHandlers(deviceStoreHandlers);
this.deviceStore = deviceStore;
DeviceProperties deviceProperties = GWT.create(DeviceProperties.class);
deviceCombo = new ComboBox<Device>(deviceStore, deviceProperties.label());
PositionProperties positionProperties = GWT.create(PositionProperties.class);
List<ColumnConfig<Position, ?>> columnConfigList = new LinkedList<ColumnConfig<Position, ?>>();