public function sign($path)
	{
		$delimiter = strpos($path, '?') === false ? '?' : '&';
		$path .= $delimiter . self::HMAC_TIMESTAMP_QUERY . '=' . time();
		$sign = hash_hmac('sha1', $path, $this->secretKey);
		$path .= '&' . self::HMAC_SIGN_QUERY . '=' . $sign;
		return $path;
	}