How to use the @igo2/geo.FeatureType.DataSource function in @igo2/geo

handleFeatureSelect(feature: Feature) {
    if (feature.type === FeatureType.Feature) {
      this.overlayService.setFeatures([feature], OverlayAction.ZoomIfOutMapExtent);
    } else if (feature.type === FeatureType.DataSource) {
      const map = this.mapService.getMap();
      if (map !== undefined) {
        this.layerService
          .createAsyncLayer(feature.layer)
          .subscribe(layer => {
            map.addLayer(layer);
          });
      }
    }
  }
}