layer at (0,0) size 800x600
  LayoutView at (0,0) size 800x600
layer at (0,0) size 800x20
  LayoutBlockFlow {svg} at (0,0) size 800x20 [color=#008000]
    LayoutInline {rect} at (0,0) size 0x0
    LayoutText {#text} at (0,0) size 152x19
      text run at (0,0) width 152: "This line should be green."