# File lib/fakefs/file_system.rb, line 39
    def add(path, object = FakeDir.new)
      parts = path_parts(normalize_path(path))

      d = parts[0...-1].reduce(fs) do |dir, part|
        assert_dir dir[part] if dir[part]
        dir[part] ||= FakeDir.new(part, dir)
      end

      assert_dir d
      object.name = parts.last
      object.parent = d
      d[parts.last] ||= object
    end