docs: @Pure
  	public final boolean isTemporaryLayer() {
  		MapLayer layer = this;
  		GISLayerContainer<?> container;
  		while (layer != null) {
  			if (layer.isTemp) {
  				return true;
  			}
  			container = layer.getContainer();
  			layer = container instanceof MapLayer ? (MapLayer) container : null;
  		}
  		return false;
  	}