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 {P} at (0,0) size 784x28
        RenderText {TEXT} at (0,0) size 12x28
          text run at (0,0) width 12: "x"
selection is CARET:
start:      position 1 of child 1 {TEXT} of child 1 {P} of root {BODY}
upstream:   position 1 of child 1 {TEXT} of child 1 {P} of root {BODY}
downstream: position 1 of child 1 {TEXT} of child 1 {P} of root {BODY}