docs: public void addMapStartZoom(String zoom) {
          if (zoom != null) {
              try {
                  int intZoom = Integer.parseInt(zoom);
                  if (intZoom < 0 || intZoom > 21) {
                      throw new IllegalArgumentException("not a valid map start zoom: " + zoom);
                  }
                  setMapStartZoomLevel(intZoom);
              } catch (NumberFormatException e) {
                  throw new IllegalArgumentException("not a valid map start zoom: " + zoom, e);
              }
          } else {
              setMapStartZoomLevel(-1);
          }
      }