@Test
public void getLayerIdsShouldReturnStringArrayWithLayerIds() {

    float textSize = 20f;
    float boundaryWidth = 6f;
    int colorInt = Color.GREEN;
    String labelProperty = "district-name";
    FeatureCollection featureCollection = FeatureCollection.fromFeatures(new ArrayList<Feature>());
    BoundaryLayer boundaryLayer = new BoundaryLayer.Builder(featureCollection)
            .setLabelProperty(labelProperty)
            .setLabelTextSize(textSize)
            .setLabelColorInt(colorInt)
            .setBoundaryColor(colorInt)
            .setBoundaryWidth(boundaryWidth)
            .build();
    String[] layerIds = boundaryLayer.getLayerIds();
    assertEquals(2, layerIds.length);
    assertNotNull(layerIds[0]);
    assertNotNull(layerIds[1]);
}