anchor.diff:    (close-tcp-connection (tcp-stream-connection stream)))
   
   (defmethod open-stream-p ((stream tcp-octet-stream))
  -  (member (tcp-connection-state (tcp-stream-connection stream))
  -          '(:established :syn-received :syn-sent)))
  +  (not (tcp-connection-closed-p stream)))
   
   (defmethod stream-element-type ((stream tcp-octet-stream))
     '(unsigned-byte 8))
  
positive.code:                       sys.gray:unread-char-mixin)
    ())
  
  (defmethod sys.gray:stream-listen ((stream tcp-stream))
    (with-tcp-connection-locked (tcp-stream-connection stream)
      (refill-tcp-packet-buffer stream)
      (not (null (tcp-stream-packet stream)))))
  
  (defmethod sys.gray:stream-read-byte ((stream tcp-octet-stream))
  
negative.code:             (not (member (tcp-connection-state connection)
                           '(:established :syn-received :syn-sent)))))
        ;; Something may have refilled while we were waiting.
        (when (tcp-stream-packet stream)
          (return-from refill-tcp-packet-buffer t))
        (when (and (null (tcp-connection-rx-data connection))
                   (not (member (tcp-connection-state connection)
                                '(:established :syn-received :syn-sent))))
  