anchor.diff:     (response-code :accessor response-code :initform "200 OK" :initarg :response-code)
      (cookie :accessor cookie :initform nil :initarg :cookie)
      (cache-control :accessor cache-control :initform nil)
  -   (keep-alive? :accessor keep-alive? :initform nil)
  +   (keep-alive? :accessor keep-alive? :initform nil :initarg :keep-alive?)
      (expires :accessor expires :initform nil)
      (body :accessor body :initform nil :initarg :body)))
  +
  +(defclass sse ()
  +  ((id :reader id :initarg :id :initform nil)
  +   (event :reader event :initarg :event :initform nil)
  +   (retry :reader retry :initarg :retry :initform nil)
  +   (data :reader data :initarg :data)))
   
   ;;;;;;;;;; HTTP error definitions
   (defparameter +404+
  
positive.code:   (write-char #\linefeed stream)
    (values))
  
  (defmethod write! ((res response) (stream stream))
    (flet ((write-ln (&rest strings)
  	   (mapc (lambda (str) (write-string str stream)) strings)
  
negative.code:       (write-ln "Set-Cookie: " it))
      (when (keep-alive? res) 
        (write-ln "Connection: keep-alive")
        (write-ln "Date: " (http-date))
        (write-ln "Expires: Thu, 01 Jan 1970 00:00:01 GMT"))
      (awhen (body res)
        (write-ln "Content-Length: " (write-to-string (length it))) (crlf stream)
  