cookies_setup = ({ href, headers } = {}) => {
	const url = new URL(href || 'https://example.com');
	const request = new Request(url, {
		headers: new Headers({
			cookie: 'a=b;',
			...headers
		})
	});
	const result = get_cookies(request, url);
	result.set_trailing_slash('ignore');
	return result;
}
@param {{ href?: string, headers?: Record<string, string> }} href