code: private static @Nullable Collection<IOException> deleteDirectoryContentsSecure(
        SecureDirectoryStream<Path> dir) {
      Collection<IOException> exceptions = null;
      try {
        for (Path path : dir) {
          exceptions = concat(exceptions, deleteRecursivelySecure(dir, path.getFileName()));
        }
  
        return exceptions;
      } catch (DirectoryIteratorException e) {
        return addException(exceptions, e.getCause());
      }
    }
docs: Secure method for deleting the contents of a directory using {@code SecureDirectoryStream}.
  Returns a collection of exceptions that occurred or null if no exceptions were thrown.