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+0 127 0+0+0] [BFC] children: not-inline
    BlockContainer <body> at [8,8] [8+0+0 784 0+0+8] [8+0+0 111 0+0+8] children: not-inline
      BlockContainer <div.upper> at [8,8] [0+0+0 784 0+0+0] [0+0+0 18 0+0+75] children: inline
        frag 0 from TextNode start: 0, length: 5, rect: [8,8 46.15625x18] baseline: 13.796875
            "upper"
        TextNode <#text> (not painted)
      BlockContainer <div.mystery> at [8,101] [0+0+0 784 0+0+0] [0+0+0 0 0+0+0] children: not-inline
      BlockContainer <div.lower> at [8,101] [0+0+0 784 0+0+0] [0+0+0 18 0+0+0] children: inline
        frag 0 from TextNode start: 0, length: 5, rect: [8,101 43.359375x18] baseline: 13.796875
            "lower"
        TextNode <#text> (not painted)

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x127]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x111]
      PaintableWithLines (BlockContainer<DIV>.upper) [8,8 784x18]
        TextPaintable (TextNode<#text>)
      PaintableWithLines (BlockContainer<DIV>.mystery) [8,101 784x0]
      PaintableWithLines (BlockContainer<DIV>.lower) [8,101 784x18]
        TextPaintable (TextNode<#text>)

SC for Viewport<#document> [0,0 800x600] [children: 1] (z-index: auto)
 SC for BlockContainer<HTML> [0,0 800x127] [children: 0] (z-index: auto)
