Viewport <#document> at (0,0) content-size 800x600 children: not-inline
  BlockContainer <html> at (1,1) content-size 798x70 [BFC] children: not-inline
    Box <body> at (10,10) content-size 200x52 [GFC] children: not-inline
      BlockContainer <div.item> at (11,11) content-size 100x50 [BFC] children: not-inline

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x72]
    PaintableBox (Box<BODY>) [9,9 202x54]
      PaintableWithLines (BlockContainer<DIV>.item) [10,10 102x52]
