src/vs/base/common/arrays.ts/CallbackIterable/findFirst
class CallbackIterable:	findFirst(predicate: (item: T) => boolean): T | undefined {
		let result: T | undefined;
		this.iterate(item => {
			if (predicate(item)) {
				result = item;
				return false;
			}
			return true;
		});
		return result;
	}