anchor.diff:             (warn "Do not know how to handle content type: ~a" type)
              body))))
   
  -(defun create-authorization-header (method request-url parameters)
  +(defun create-authorization-header (method request-url oauth-parameters parameters)
     (assert (not (null *oauth-consumer-key*)) (*oauth-consumer-key*)
             'oauth-parameter-missing :parameter '*oauth-consumer-key*)
     (assert (not (null *oauth-signature-method*)) (*oauth-signature-method*)
  
positive.code:   (assert (not (null *oauth-version*)) (*oauth-version*)
            'oauth-parameter-missing :parameter '*oauth-version*)
    (let* ((oauth-parameters (append
                              `(("oauth_consumer_key" . ,*oauth-consumer-key*)
                                ("oauth_nonce" . ,(generate-nonce))
                                ("oauth_signature_method" . ,*oauth-signature-method*)
  
negative.code:   "Finishes the authentication procedure by retrieving the access token.
  Sets the *OAUTH-TOKEN* and *OAUTH-TOKEN-SECRET* to their respective values."
    (setf *oauth-token* token)
    (let ((data (oauth/access-token verifier)))
      (setf *oauth-token* (cdr (assoc :oauth-token data))
            *oauth-token-secret* (cdr (assoc :oauth-token-secret data)))
      (values *oauth-token* *oauth-token-secret*)))
  