anchor.diff:    (typep x 'output-record))
   
   (defclass displayed-output-record (standard-bounding-rectangle output-record-mixin)
  -  ((ink :initarg :ink :reader displayed-output-record-ink)))
  +  ((ink :initarg :ink :reader displayed-output-record-ink)
  +   (initial-x1 :initarg :initial-x1)
  +   (initial-y1 :initarg :initial-y1)))
   
   (defun displayed-output-record-p (x)
     (typep x 'displayed-output-record))
  
positive.code:   ((stream output-recording-stream) continuation record draw)
    "Calls CONTINUATION on STREAM enabling or disabling recording and drawing
  according to the flags RECORD and DRAW."
    (with-slots (recording-p drawing-p) stream
                (let ((old-record recording-p)
                      (old-draw drawing-p))
                  (unwind-protect
                      (progn
                        (setq recording-p record
                              drawing-p draw)
                        (funcall continuation stream))
                    (setq recording-p old-record
                          drawing-p old-draw)))))
  
  (defmacro with-new-output-record ((stream
                                     &optional
                                     (record-type ''standard-sequence-output-record)
                                     (record nil record-supplied-p)
                                     &rest initargs)
                                    &body body)
  
negative.code: (defmacro with-output-recording-options ((stream &key (record t) (draw t)) &body body)
    (declare (type symbol stream))
    (when (eq stream 't)
      (setq stream '*standard-output*))
    (let ((continuation-name (gensym)))
      `(let ((,continuation-name #'(lambda (,stream) ,@body)))
         (invoke-with-output-recording-options ,stream
  