docs: public static TileCache createTileCache(int tileSize, double overdrawFactor, int capacity, File cacheDirectory) {
          int cacheSize = getMinimumCacheSize(tileSize, overdrawFactor);
          TileCache firstLevelTileCache = new InMemoryTileCache(cacheSize);
          TileCache secondLevelTileCache = new FileSystemTileCache(capacity, cacheDirectory, AwtGraphicFactory.INSTANCE);
          return new TwoLevelTileCache(firstLevelTileCache, secondLevelTileCache);
      }