anchor.diff:                     (ob output-buffer-of)
                      (dirtyp dirtyp))
         stream
  -    (%flush-obuf write-fn fd ob)
  -    (setf dirtyp nil)
  -    nil))
  +    (%write-octets-from-iobuf write-fn fd ob)
  +    (setf dirtyp nil)))
   
   (defmethod stream-force-output ((stream dual-channel-gray-stream))
     (setf (dirtyp stream) t))
  
positive.code:                    (dirtyp dirtyp))
        stream
      (when (or dirtyp (iobuf-full-p ob))
        (%flush-obuf write-fn fd ob)
        (setf dirtyp nil))))
  
  (defmethod stream-clear-output ((stream dual-channel-gray-stream))
  
negative.code: 
  (defmethod stream-write-char ((stream dual-channel-gray-stream)
                                (character character))
    (flush-obuf-if-needed stream)
    (if (char= character #\Newline)
        (%write-line-terminator
         stream (babel:external-format-eol-style (external-format-of stream)))
  