Viewport <#document> at (0,0) content-size 800x600 children: not-inline
  BlockContainer <html> at (1,1) content-size 798x68 [BFC] children: not-inline
    Box <body.flex> at (10,10) content-size 38.84375x50 flex-container(row) [FFC] children: not-inline
      BlockContainer <div.item> at (11,11) content-size 36.84375x48 flex-item [BFC] children: inline
        frag 0 from TextNode start: 0, length: 5, rect: [11,11 36.84375x17] baseline: 13.296875
            "hello"
        TextNode <#text>

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x70]
    PaintableBox (Box<BODY>.flex) [9,9 40.84375x52]
      PaintableWithLines (BlockContainer<DIV>.item) [10,10 38.84375x50]
        TextPaintable (TextNode<#text>)
