layer at (0,0) size 800x600
  RenderView at (0,0) size 800x600
layer at (0,0) size 800x600
  RenderBlock {HTML} at (0,0) size 800x600
    RenderBody {BODY} at (8,8) size 784x576
      RenderBlock {P} at (0,0) size 784x17
        RenderText {#text} at (0,0) size 318x17
          text run at (0,0) width 318: "This tests that attachments have a custom renderer."
      RenderBlock (anonymous) at (0,33) size 784x0
        RenderInline {ATTACHMENT} at (0,0) size 0x0
        RenderText {#text} at (0,0) size 0x0