function subsequent_fetch(resource, resolved, opts) {
	if (cache.size > 0) {
		const selector = build_selector(resource, opts);
		const cached = cache.get(selector);
		if (cached) {
			// https://developer.mozilla.org/en-US/docs/Web/API/Request/cache#value
			if (
				performance.now() < cached.ttl &&
				['default', 'force-cache', 'only-if-cached', undefined].includes(opts?.cache)
			) {
				return new Response(cached.body, cached.init);
			}

			cache.delete(selector);
		}
	}

	return DEV ? dev_fetch(resolved, opts) : window.fetch(resolved, opts);
}
Tries to get the response from the cache, if max-age allows it, else does a fetch.
@param {URL | string} resource
@param {string} resolved
@param {RequestInit} [opts]