docs: public CacheManagerTask downloadAreaAsyncNoUI(Context ctx, BoundingBox bb, final int zoomMin, final int zoomMax, final CacheManagerCallback callback) {
          final CacheManagerTask task = new CacheManagerTask(this, getDownloadingAction(), bb, zoomMin, zoomMax);
          task.addCallback(callback);
          execute(task);
          return task;
      }