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 784x84 [border: (2px solid #FF0000)]
        RenderInline {SPAN} at (0,0) size 34x56
          RenderText {TEXT} at (14,14) size 34x28
            text run at (14,14) width 34: "test"
          RenderBR {BR} at (0,0) size 0x0
          RenderText {TEXT} at (14,42) size 12x28
            text run at (14,42) width 12: "x"
          RenderBR {BR} at (0,0) size 0x0
        RenderText {TEXT} at (0,0) size 0x0
selection is CARET:
start:      position 1 of child 3 {TEXT} of child 2 {SPAN} of root {DIV}
upstream:   position 1 of child 3 {TEXT} of child 2 {SPAN} of root {DIV}
downstream: position 0 of child 4 {BR} of child 2 {SPAN} of root {DIV}
