Viewport <#document> at (0,0) content-size 800x600 children: not-inline
  BlockContainer <html> at (1,1) content-size 798x119 [BFC] children: not-inline
    BlockContainer <body> at (10,10) content-size 500x101 children: not-inline
      BlockContainer <div.a> at (31,21) content-size 458x79 children: not-inline
        BlockContainer <div.b> at (72,52) content-size 376x17 children: inline
          InlineNode <span>
            frag 0 from TextNode start: 0, length: 5, rect: [73,52 39.78125x17] baseline: 13.296875
                "Hello"
            TextNode <#text>

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x121]
    PaintableWithLines (BlockContainer<BODY>) [9,9 502x103]
      PaintableWithLines (BlockContainer<DIV>.a) [10,10 500x101]
        PaintableWithLines (BlockContainer<DIV>.b) [71,51 378x19]
          PaintableWithLines (InlineNode<SPAN>)
            TextPaintable (TextNode<#text>)
