docs: @SuppressWarnings("deprecation")
      @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
      public static long getAvailableCacheSlots(String directory, int fileSize) {
          StatFs statfs = new StatFs(directory);
          if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
              return statfs.getAvailableBytes() / fileSize;
          }
          // problem is overflow with devices with large storage, so order is important here
          // additionally avoid division by zero in devices with a large block size
          int blocksPerFile = Math.max(fileSize / statfs.getBlockSize(), 1);
          return statfs.getAvailableBlocks() / blocksPerFile;
      }