private function addRegexpRoute($expression, $route)
    {
        $expression = '|^'.str_replace(array('*', '\\'), array('.*', '\\\\'), $expression).'$|i';
        if (array_key_exists($expression, $this->regexpRoutes) && $this->regexpRoutes[$expression] == $route) {
            return false;
        }
        $this->regexpRoutes[$expression] = (string) $route;
        return true;
    }