layer at (0,0) size 800x600
  RenderView at (0,0) size 800x600
layer at (0,0) size 800x40
  RenderBlock {HTML} at (0,0) size 800x40
    RenderBody {BODY} at (8,8) size 784x24 [color=#0000001A]
      RenderText {#text} at (0,8) size 16x16
        text run at (0,8) width 16: "a"
      RenderRuby (inline) {RUBY} at (0,0) size 64x16
        RenderRubyRun (anonymous) at (16,8) size 16x16
          RenderRubyText {RT} at (0,-8) size 16x8
            RenderText {#text} at (4,0) size 8x8
              text run at (4,0) width 8: "1"
          RenderRubyBase (anonymous) at (0,0) size 16x16
            RenderText {#text} at (0,0) size 16x16
              text run at (0,0) width 16: "1"
        RenderRubyRun (anonymous) at (32,8) size 16x16
          RenderRubyText {RT} at (0,-8) size 16x8
            RenderText {#text} at (4,0) size 8x8
              text run at (4,0) width 8: "2"
          RenderRubyBase (anonymous) at (0,0) size 16x16
            RenderText {#text} at (0,0) size 16x16
              text run at (0,0) width 16: "2"
        RenderRubyRun (anonymous) at (48,8) size 16x16
          RenderRubyText {RT} at (0,-8) size 16x8
            RenderText {#text} at (4,0) size 8x8
              text run at (4,0) width 8: "3"
          RenderRubyBase (anonymous) at (0,0) size 16x16
            RenderText {#text} at (0,0) size 16x16
              text run at (0,0) width 16: "3"
        RenderRubyRun (anonymous) at (64,8) size 16x16
          RenderRubyText {RT} at (0,-8) size 16x8
            RenderText {#text} at (4,0) size 8x8
              text run at (4,0) width 8: "4"
          RenderRubyBase (anonymous) at (0,0) size 16x16
            RenderText {#text} at (0,0) size 16x16
              text run at (0,0) width 16: "4"
      RenderText {#text} at (80,8) size 16x16
        text run at (80,8) width 16: "b"
      RenderText {#text} at (0,0) size 0x0
selection start: position 1 of child 2 {#text} of body
selection end:   position 1 of child 4 {#text} of body