code: public static function generateToken($token_name = self::TOKEN_NAME)
  	{
  		// generate as random of a token as possible
  		$salt   = !empty($_SERVER['REMOTE_ADDR']) ? $_SERVER['REMOTE_ADDR'] : uniqid();
  		$_SESSION[$token_name]  = sha1(uniqid(sha1($salt), true));
  	}
docs: (Re-)Generate a token and write it to session
  
  @param string $token_name - defaults to the default token name
  @return void