anchor.diff:  			 (event window-manager-delete-event))
     (frame-exit (pane-frame (event-sheet event))))
   
  -;;;; UNMANAGED-TOP-LEVEL-SHEET-PANE
  +;;;; UNMANAGED-TOP-LEVEL-SHEET PANE
   
   (defclass unmanaged-top-level-sheet-pane (top-level-sheet-pane)
     ()
  
positive.code: 
  (defmethod pane-viewport ((pane basic-pane))
    (let ((parent (sheet-parent pane)))
      (if (and parent (typep parent 'viewport-pane))
  	parent
        nil)))
  
  ;;; Default for streams that aren't even panes.
  
  
negative.code: 
  (defmacro bordering ((&rest options) &body contents)
    `(make-pane 'border-pane ,@options :contents (list ,@contents)))
  
  (defmethod pane-border ((pane basic-pane))
    (let ((parent (sheet-parent pane)))
      (when (and parent (typep parent 'border-pane))
  	parent)))
  
  ;;; RAISED PANE
  
  