anchor.diff:             (path (getf env :path-info)))
         (when (null uid) (setf (gethash :prev-url session) path))
         `(200 (:content-type "text/html")
  -            ,(append (page-header)
  +            ,(append (page-header env)
                        (status uid)
                        (list "<p>path = " path "</p>")
                        (page-footer))))))
  
positive.code: (defun get-uid (env)
    (gethash :uid (getf env :lack.session)))
  
  (defun page-header ()
    '("<html><h1>Lack Session Middleware Test</h1>
     <h2>--- Login Logout Example ---</h2>
     <p>Access any directories.  Any directories under '<b>/private</b>' needs to be logged in to access.</p>
     <hr />
     "))
  
  (defun status (uid)
    (if uid
  
negative.code:            ;; /privateにmountしているのでpathには/privateが含まれない
             (path (concatenate 'string "/private" (getf env :path-info))))
        `(200 (:content-type "text/html")
              ,(append (page-header env)
                       (status uid)
                       (list "<p>Private Area: path = " path "</p>")
                       (page-footer))))))
  