Viewport <#document> at (0,0) content-size 800x600 children: not-inline
  BlockContainer <html> at (0,0) content-size 800x600 [BFC] children: not-inline
    BlockContainer <body> at (8,8) content-size 784x18 children: inline
      frag 0 from BlockContainer start: 0, length: 0, rect: [13,19 0x0] baseline: 4
      BlockContainer <button#button> at (13,19) content-size 0x0 inline-block [BFC] children: not-inline
        BlockContainer <(anonymous)> at (13,19) content-size 0x0 flex-container(column) [FFC] children: not-inline
          BlockContainer <(anonymous)> at (13,19) content-size 0x0 [BFC] children: not-inline
      TextNode <#text>
      TextNode <#text>
      TextNode <#text>
  BlockContainer <(anonymous)> at (0,0) content-size 800x600 positioned [BFC] children: not-inline
  BlockContainer <div#pop> at (358.84375,291) content-size 82.3125x18 positioned [BFC] children: inline
    TextNode <#text>
    InlineNode <span>
      frag 0 from TextNode start: 0, length: 10, rect: [358.84375,291 82.3125x18] baseline: 13.796875
          "I'm a node"
      TextNode <#text>
    TextNode <#text>

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x600]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x18]
      PaintableWithLines (BlockContainer<BUTTON>#button) [8,17 10x4]
        PaintableWithLines (BlockContainer(anonymous)) [13,19 0x0]
          PaintableWithLines (BlockContainer(anonymous)) [13,19 0x0]
  PaintableWithLines (BlockContainer(anonymous)) [0,0 800x600]
  PaintableWithLines (BlockContainer<DIV>#pop) [351.84375,284 96.3125x32]
    PaintableWithLines (InlineNode<SPAN>)
      TextPaintable (TextNode<#text>)
