[0] index.html Root
  [0:0] 1.html Child1
    [0:0:0] friendly_url.html FriendlyUrl
      [0:0:0:0] 3.html Child3
        [0:0:0:0:0] 31.html Child31
        [0:0:0:0:1] 32.html Child32
  [0:1] 2.html Child2
    [0:1:0] 21.html Child21
    [0:1:1] 22.html Child22
