docs: @SuppressLint("DeprecatedMethod")
    public long getFreeStorageSpace(StorageType storageType) {
      ensureInitialized();
  
      maybeUpdateStats();
  
      StatFs statFS = storageType == StorageType.INTERNAL ? mInternalStatFs : mExternalStatFs;
      if (statFS != null) {
        long blockSize, availableBlocks;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
          blockSize = statFS.getBlockSizeLong();
          availableBlocks = statFS.getFreeBlocksLong();
        } else {
          blockSize = statFS.getBlockSize();
          availableBlocks = statFS.getFreeBlocks();
        }
        return blockSize * availableBlocks;
      }
      return -1;
    }