code: @Nullable
    private DirectoryEntry lookUpLast(
        @Nullable File dir, Name name, Set<? super LinkOption> options, int linkDepth)
        throws IOException {
      Directory directory = toDirectory(dir);
      if (directory == null) {
        return null;
      }
  
      DirectoryEntry entry = directory.get(name);
      if (entry == null) {
        return new DirectoryEntry(directory, name, null);
      }
  
      File file = entry.file();
      if (!options.contains(LinkOption.NOFOLLOW_LINKS) && file.isSymbolicLink()) {
        return followSymbolicLink(dir, (SymbolicLink) file, linkDepth);
      }
  
      return getRealEntry(entry);
    }
docs: Looks up the last element of a path.