src/vs/base/common/map.ts/UriIterator/next
class UriIterator:	next(): this {
		if (this._states[this._stateIdx] === UriIteratorState.Path && this._pathIterator.hasNext()) {
			this._pathIterator.next();
		} else {
			this._stateIdx += 1;
		}
		return this;
	}