CAS_Client::setSingleSignoutCallback PHP Method

    public function setSingleSignoutCallback($function, array $additionalArgs = array())
    {
        $this->_signoutCallbackFunction = $function;
        $this->_signoutCallbackArgs = $additionalArgs;
    }

 /**
  * Set a callback function to be run when a single-signout request is
  * received. The callback function will be passed a $logoutTicket as its
  * first parameter, followed by any $additionalArgs you pass. The
  * $logoutTicket parameter is an opaque string that can be used to map a
  * session-id to the logout request in order to support single-signout in
  * applications that manage their own sessions (rather than letting phpCAS
  * start and destroy the session).
  *
  * @param string $function       Callback function
  * @param array  $additionalArgs optional array of arguments
  *
  * @return void
  */
 public static function setSingleSignoutCallback($function, array $additionalArgs = array())
 {
     phpCAS::_validateClientExists();
     self::$_PHPCAS_CLIENT->setSingleSignoutCallback($function, $additionalArgs);
 }