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 0 0+0+0] [BFC] children: not-inline
    BlockContainer <body> at [0,0] [0+0+0 800 0+0+0] [0+0+0 0 0+0+0] children: not-inline
      BlockContainer <div> at [0,0] positioned [0+0+0 800 0+0+0] [0+0+0 0 0+0+0] children: inline
        InlineNode <span> at [0,0] [0+0+5 0 5+0+0] [0+0+5 20 5+0+0]
          BlockContainer <b> at [0,0] positioned [0+0+0 10 0+0+0] [0+0+0 20 0+0+0] [BFC] children: inline
            frag 0 from TextNode start: 0, length: 1, rect: [0,5 10x10] baseline: 8
                "X"
            TextNode <#text> (not painted)
      BlockContainer <(anonymous)> at [0,0] [0+0+0 800 0+0+0] [0+0+0 0 0+0+0] children: inline
        TextNode <#text> (not painted)

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x0]
    PaintableWithLines (BlockContainer<BODY>) [0,0 800x0]
      PaintableWithLines (BlockContainer<DIV>) [0,0 800x0]
        InlinePaintable (InlineNode<SPAN>) [-5,-5 10x30]
          PaintableWithLines (BlockContainer<B>) [0,0 10x20]
      PaintableWithLines (BlockContainer(anonymous)) [0,0 800x0]

SC for Viewport<#document> [0,0 800x600] (z-index: auto)
 SC for BlockContainer<HTML> [0,0 800x0] (z-index: auto)
