private static @Nullable Entry mapPathPrefix(Entry e, List<String> prefix) throws IOException {
    List<String> ourPathSplit = normalizePathAndSplit(e.name);
    if (prefix.size() >= ourPathSplit.size() || !ourPathSplit.subList(0, prefix.size()).equals(prefix)) {
      return null;
    }
    String newName = String.join("/", ourPathSplit.subList(prefix.size(), ourPathSplit.size()));
    return new Entry(newName, e.type, e.mode, e.linkTarget, e.size);
  }
private static @Nullable Entry mapPathPrefix(Entry e, List<String> prefix)