@Test
public void getLayerIdsShouldReturnStringArrayWithLayerIds() throws InvalidArrowLineConfigException {

    ArrayList<Feature> featuresList = new ArrayList<>();
    FeatureCollection featureCollection = FeatureCollection.fromFeatures(featuresList);
    ArrowLineLayer.FeatureConfig featureConfig = new ArrowLineLayer.FeatureConfig(featureCollection);
    ArrowLineLayer.SortConfig sortConfig = new ArrowLineLayer.SortConfig("", ArrowLineLayer.SortConfig.SortOrder.DESC, ArrowLineLayer.SortConfig.PropertyType.NUMBER);
    ArrowLineLayer.Builder builder = new ArrowLineLayer.Builder(context, featureConfig, sortConfig);
    ArrowLineLayer arrowLineLayer = builder.build();
    String[] layerIds = arrowLineLayer.getLayerIds();
    assertEquals(2, layerIds.length);
    assertNotNull(layerIds[0]);
    assertNotNull(layerIds[1]);
}