pod
  head1
    @title
      "1"
    head2
      @title
        "1.1"
      head3
        @title
          "1.1.1"
        head4
          @title
            "1.1.1.1"
        head4
          @title
            "1.1.1.2"
      head3
        @title
          "1.1.2"
      head3
        @title
          "1.1.3"
      head3
        @title
          "1.1.4"
        head4
          @title
            "1.1.4.1"
    head2
      @title
        "1.2"
    head2
      @title
        "1.3"
  head1
    @title
      "2"
  head1
    @title
      "3"
    head4
      @title
        "3.0.0.1"
    head4
      @title
        "3.0.0.2"
    head3
      @title
        "3.0.1"
    head2
      @title
        "3.1"
      head4
        @title
          "3.1.0.1"
      head4
        @title
          "3.1.0.2"
  head1
    @title
      "4"