public function echoHeader() {
        if ($this->status != 200) {
            http_response_code($this->status);
        } else if (defined('CACHE_EXPIRE') && CACHE_EXPIRE) {
            Response::cache(CACHE_EXPIRE);
        }
        if (!empty ($this->headers) && is_array($this->headers)) {
            foreach ($this->headers as $name => $value) {
                @header("$name: $value", true);
            }
        }
    }