### Question:
GeoJsonRenderer extends Renderer implements Observer { public void addFeature(GeoJsonFeature feature) { super.addFeature(feature); if (isLayerOnMap()) { feature.addObserver(this); } } GeoJsonRenderer(GoogleMap map, HashMap<GeoJsonFeature, Object> features, MarkerManager markerManager, PolygonManager polygonManager, PolylineManager polylineManager, GroundOverlayManager groundOverlayManager); void setMap(GoogleMap map); void addLayerToMap(); void addFeature(GeoJsonFeature feature); void removeLayerFromMap(); void removeFeature(GeoJsonFeature feature); void update(Observable observable, Object data);  }### Answer:
@Test public void testAddFeature() { mRenderer.addFeature(mGeoJsonFeature); assertTrue(mRenderer.getFeatures().contains(mGeoJsonFeature)); }