anchor.diff:        (error "No session token set in ~S"
                '*credentials*))
       (ensure-header "x-amz-date" (rfc1123-timestamp) request)
  -    (ensure-header "x-amz-security-token" token request)))
  +    (ensure-header "x-amz-security-token" token request))
  +  request)
   
   (defun json-auth-v3-headers (request)
     (let ((headers (sort (copy-list
  
positive.code:   (delete-parameter "Signature" request)
    (let ((token (session-token *credentials*)))
      (when token
        (ensure-parameter "SecurityToken" token request))))
  
  (defmethod vector-to-sign ((request query-auth-v2))
    (with-octet-sink (sink)
  
negative.code:   (let ((token (session-token *credentials*)))
      (when token
        (ensure-header "x-amz-security-token" token request)))
    (ensure-header "x-amz-date" (rfc1123-timestamp) request)
    request)
  
  (defmethod string-to-sign ((request query-auth-v3))
    (header-value "x-amz-date" request))
  