src/vs/platform/policy/common/filePolicyService.ts/keysDiff
function keysDiff<T>(a: Map<string, T>, b: Map<string, T>): string[] {
	const result: string[] = [];

	for (const key of Iterable.concat(a.keys(), b.keys())) {
		if (a.get(key) !== b.get(key)) {
			result.push(key);
		}
	}

	return result;
}