private String placeLayerBelow() {
    if (belowLayer == null || belowLayer.isEmpty()) {
      List<Layer> styleLayers = style.getLayers();
      Layer layer;
      for (int i = styleLayers.size() - 1; i >= 0; i--) {
        layer = styleLayers.get(i);
        if (!(layer instanceof SymbolLayer)) {
          return layer.getId();
        }
      }
    }
    return belowLayer;
  }
private String placeLayerBelow ( ) { if ( belowLayer == null || belowLayer . isEmpty ( ) ) { List < Layer > styleLayers = style . getLayers ( ) ; Layer layer ; for ( int i = styleLayers . size ( ) - 1 ; i >= 0 ; i -- ) { layer = styleLayers . get ( i ) ; if ( ! ( layer instanceof SymbolLayer ) ) { return layer . getId ( ) ; } } } return belowLayer ; }
Attempts to find the layer which the traffic should be placed below. Depending on the style, this might not always
be accurate.