docs: public static ArrayList<InfoWindow> getOpenedInfoWindowsOn(MapView mapView) {
          int count = mapView.getChildCount();
          ArrayList<InfoWindow> opened = new ArrayList<InfoWindow>(count);
          for (int i = 0; i < count; i++) {
              final View child = mapView.getChildAt(i);
              Object tag = child.getTag();
              if (tag != null && tag instanceof InfoWindow) {
                  InfoWindow infoWindow = (InfoWindow) tag;
                  opened.add(infoWindow);
              }
          }
          return opened;
      }