anchor.diff:    (unless (floating-window-p window)
       (first (sort (lem-utils:min-if #'window-y
                                      (remove-if-not (lambda (w)
  -                                                    (>= (window-y w) (+ (window-y window) (window-height window))))
  +                                                    (>= (window-y w)
  +                                                        (+ (window-y window)
  +                                                           (window-height window))))
                                                     (window-list)))
                    (difference-window-x window)))))
   
  
positive.code:     (first (sort (lem-utils:min-if #'window-x
                                     (remove-if-not (lambda (w)
                                                      (> (window-x w)
                                                         (+ (window-x window) (window-width window))))
                                                    (window-list)))
                   (difference-window-y window)))))
  
  
negative.code:     (error "floating window is not supported"))
    (setf (frame-modified-floating-windows (current-frame)) t))
  
  (defmethod initialize-instance :after ((floating-window floating-window)
                                         &key (frame (current-frame)) &allow-other-keys)
    (alexandria:appendf (frame-floating-windows frame)
                        (list floating-window)))
  
  