extensions/html-language-features/client/src/customData.ts/hasChanges
function hasChanges(s1: Set<string>, s2: Set<string>) {
	if (s1.size !== s2.size) {
		return true;
	}
	for (const uri of s1) {
		if (!s2.has(uri)) {
			return true;
		}
	}
	return false;
}