anchor.diff:          (car (buffer-list))
           (car buffer-list))))
   
  +;;; switch-to-buffer/pop-to-buffer
   (defun run-show-buffer-hooks (window)
     (when (window-parameter window 'change-buffer)
       (setf (window-parameter window 'change-buffer) nil)
  
positive.code: (defun floating-window-p (window)
    (typep window 'floating-window))
  
  (defclass header-window (window) ())
  
  (defmethod initialize-instance ((window header-window) &key &allow-other-keys)
  
negative.code: (defparameter *use-new-vertical-move-function* t)
  (defparameter *use-cursor-movement-workaround* t)
  
  (defgeneric %delete-window (window))
  
  (defclass window ()
    ((x
      :initarg :x
  