public function set($type = null, $key = null, $value = null)
    {
        if (isset($type)) {
            $this->request[$type]["$key"] = $value;
        } else {
            $this->request = array(
                'get' => $_GET,
                'post' => $_POST,
                'files' => $_FILES,
                'cookie' => $_COOKIE
            );
        }

        return $this;
    }