anchor.diff:  
   The specialized method may call `call-next-method' to return a sensible fallback window."))
   
  -(define-ffi-generic ffi-window-set-buffer (window buffer &key focus))
  -(define-ffi-generic ffi-window-add-panel-buffer (window buffer side))
  -(define-ffi-generic ffi-window-delete-panel-buffer (window buffer))
  +(define-ffi-generic ffi-window-set-buffer (window buffer &key focus)
  +  (:documentation "Set the BUFFER's widget to display in WINDOW.
  +If FOCUS is non-nil, "))
  +
  +(define-ffi-generic ffi-window-add-panel-buffer (window buffer side)
  +  (:documentation "Make widget for pannel BUFFER and add it to the WINDOW widget.
  +SIDE is one of `:left' or `:right'."))
  +(define-ffi-generic ffi-window-delete-panel-buffer (window buffer)
  +  (:documentation "Unbind the pannel BUFFER widget from WINDOW."))
   
   (define-ffi-generic ffi-window-panel-buffer-width (window buffer)
     (:documentation "Return the panel BUFFER width as a number.
  
positive.code:   (:documentation "Return the WINDOW message buffer height as a number.
  Setf-able."))
  
  (define-ffi-generic ffi-buffer-make (buffer))
  (define-ffi-generic ffi-buffer-delete (buffer))
  (define-ffi-generic ffi-buffer-load (buffer url))
  (define-ffi-generic ffi-buffer-evaluate-javascript (buffer javascript &optional world-name))
  (define-ffi-generic ffi-buffer-evaluate-javascript-async (buffer javascript &optional world-name))
  (define-ffi-generic ffi-buffer-add-user-style (buffer css &key
                                                        world-name all-frames-p inject-as-author-p
                                                        allow-list block-list))
  (define-ffi-generic ffi-buffer-remove-user-style (buffer style-sheet))
  (define-ffi-generic ffi-buffer-add-user-script (buffer javascript &key
                                                         world-name all-frames-p at-document-start-p
                                                         run-now-p allow-list block-list))
  (define-ffi-generic ffi-buffer-remove-user-script (buffer script))
  
  (define-ffi-generic ffi-buffer-javascript-enabled-p (buffer)
    (:documentation "Return setting as boolean.
  
negative.code: Setf-able.  The value is either a PROXY-URL or a pair of (PROXY-URL IGNORE-HOSTS).
  PROXY-URL is a `quri:uri' and IGNORE-HOSTS a list of strings."))
  
  (define-ffi-generic ffi-buffer-download (buffer url)
    (:documentation "Download URL using the BUFFER web view."))
  
  (define-ffi-generic ffi-buffer-zoom-level (buffer)
    (:method ((buffer t))
  