protected function before_user_func()
    {
        if ($this->config['error_reporting'] !== false) {
            set_error_handler(sprintf('%s::error_handler', __CLASS__), $this->config['error_reporting']);
        }

        if (empty($_POST['phery']['csrf'])) {
            $_POST['phery']['csrf'] = '';
        }

        if ($this->csrf($_POST['phery']['csrf']) === false) {
            self::exception($this, 'Invalid CSRF token', self::ERROR_CSRF);
        }
    }