Viewport <#document> at [0,0] [0+0+0 800 0+0+0] [0+0+0 600 0+0+0] children: not-inline
  BlockContainer <html> at [0,0] [0+0+0 800 0+0+0] [0+0+0 220 0+0+0] [BFC] children: not-inline
    BlockContainer <body> at [8,8] [8+0+0 784 0+0+8] [8+0+0 204 0+0+8] children: not-inline
      BlockContainer <div.a> at [9,9] [0+1+0 100 0+1+682] [0+1+0 100 0+1+0] children: not-inline
      BlockContainer <div.b> at [9,111] [0+1+0 100 0+1+682] [0+1+0 100 0+1+0] children: not-inline

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x220]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x204]
      PaintableWithLines (BlockContainer<DIV>.a) [8,8 102x102]
      PaintableWithLines (BlockContainer<DIV>.b) [8,110 102x102]

SC for Viewport<#document> [0,0 800x600] [children: 1] (z-index: auto)
 SC for BlockContainer<HTML> [0,0 800x220] [children: 0] (z-index: auto)
