anchor.diff:  If stream is a flexi-stream, its external-format will be used when
   decoding strings.  Otherwise, the value of the external-format
   parameter is used to create a flexi-stream for decoding.  The default
  -is :utf-8."))
  +is UTF-8."))
   
  -(defmethod decode ((stream stream) &key (external-format +utf-8+))
  +(defmethod decode ((stream stream) &key (external-format :utf-8))
     (decode (make-flexi-stream stream :external-format external-format)))
   
  -(defmethod decode ((sequence sequence) &key (external-format +utf-8+))
  +(defmethod decode ((sequence sequence) &key (external-format :utf-8))
     (with-input-from-sequence (stream sequence)
       (decode (make-flexi-stream stream :external-format external-format))))
   
  
positive.code: 
  (defgeneric encode (object stream &key external-format)
    (:documentation "Encode object and write it to stream or, if stream
  is nil, use an in-memory stream and return the resulting sequence."))
  
  (defmethod encode (object (stream stream) &key (external-format +utf-8+))
    (encode object (make-flexi-stream stream :external-format external-format)))
  
  (defmethod encode (object (stream (eql nil)) &key (external-format +utf-8+))
    (with-output-to-sequence (stream)
      (encode object (make-flexi-stream stream :external-format external-format))))
  
  
negative.code:             (error "Expected 0x~x got 0x~x" (char-code char) byte)))
      (continue () t)))
  
  (defun string-to-octets (string &optional (external-format :utf-8))
    (flex:string-to-octets string :external-format external-format))
  
  (defun octets-to-string (octets external-format)
  