layer at (0,0) size 800x600
  RenderCanvas at (0,0) size 800x600
layer at (0,0) size 800x600
  RenderBlock {HTML} at (0,0) size 800x600
    RenderBody {BODY} at (8,8) size 784x584
      RenderBlock {DIV} at (0,0) size 784x56 [border: (2px solid #FF0000)]
        RenderBlock (anonymous) at (14,14) size 756x28
          RenderInline {SPAN} at (0,0) size 37x28
            RenderText {TEXT} at (0,0) size 37x28
              text run at (0,0) width 37: "Foo"
        RenderBlock (anonymous) at (14,42) size 756x0
        RenderBlock (anonymous) at (14,42) size 756x0
          RenderInline {SPAN} at (0,0) size 0x0
          RenderText {TEXT} at (0,0) size 0x0
selection is CARET:
start:      position 3 of child 1 {TEXT} of child 2 {SPAN} of root {DIV}
upstream:   position 3 of child 1 {TEXT} of child 2 {SPAN} of root {DIV}
downstream: position 1 of child 3 {TEXT} of root {DIV}
