src/vs/base/common/normalization.ts/normalize
function normalize(str: string, form: string, normalizedCache: LRUCache<string, string>): string {
	if (!canNormalize || !str) {
		return str;
	}

	const cached = normalizedCache.get(str);
	if (cached) {
		return cached;
	}

	let res: string;
	if (nonAsciiCharactersPattern.test(str)) {
		res = (<any>str).normalize(form);
	} else {
		res = str;
	}

	// Use the cache for fast lookup
	normalizedCache.set(str, res);

	return res;
}