Viewport <#document> at [0,0] [0+0+0 800 0+0+0] [0+0+0 600 0+0+0] [BFC] children: not-inline
  BlockContainer <html> at [0,0] [0+0+0 800 0+0+0] [0+0+0 116 0+0+0] [BFC] children: not-inline
    BlockContainer <body> at [8,8] [8+0+0 784 0+0+8] [8+0+0 100 0+0+8] children: not-inline
      BlockContainer <div#a> at [8,8] [0+0+0 100 0+0+684] [0+0+0 100 0+0+0] children: not-inline
        BlockContainer <div#b> at [8,8] [0+0+0 100 0+0+0] [0+0+0 100 0+0+0] children: inline
          TextNode <#text> (not painted)

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x116]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x100]
      PaintableWithLines (BlockContainer<DIV>#a) [8,8 100x100]
        PaintableWithLines (BlockContainer<DIV>#b) [8,8 100x100]

SC for Viewport<#document> [0,0 800x600] [children: 1] (z-index: auto)
 SC for BlockContainer<HTML> [0,0 800x116] [children: 0] (z-index: auto)
