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
    RenderFrameSet {FRAMESET} at (0,0) size 800x600
      RenderFrame {FRAME} at (0,0) size 800x534
        layer at (0,0) size 800x534
          RenderView at (0,0) size 800x534
        layer at (0,0) size 800x534
          RenderBlock {HTML} at (0,0) size 800x534
            RenderBody {BODY} at (8,8) size 784x518
              RenderText {#text} at (0,0) size 373x19
                text run at (0,0) width 373: "This 404 error was intentionally generated by a test script."
      RenderFrame {FRAME} at (0,540) size 800x60
        layer at (0,0) size 800x92
          RenderView at (0,0) size 800x60
        layer at (0,0) size 800x92
          RenderBlock {HTML} at (0,0) size 800x92
            RenderBody {BODY} at (8,8) size 784x76
              RenderText {#text} at (0,1) size 724x74
                text run at (0,1) width 724: "This is just a minimal page that we navigate to as part of"
                text run at (0,39) width 272: "testing back/forward."

============== Back Forward List ==============
        http://127.0.0.1:8000/navigation/error404-subframeload.html  **nav target**
        http://127.0.0.1:8000/navigation/resources/frameset.pl?frameURL=otherpage.html  **nav target**
            http://127.0.0.1:8000/navigation/resources/otherpage.html (in frame "footer")
            http://127.0.0.1:8000/navigation/resources/otherpage.html (in frame "main")
curr->  http://127.0.0.1:8000/navigation/resources/frameset.pl?frameURL=otherpage.html
            http://127.0.0.1:8000/navigation/resources/otherpage.html (in frame "footer")
            http://127.0.0.1:8000/navigation/resources/error404.pl (in frame "main")  **nav target**
===============================================