src/vs/base/parts/quickinput/browser/quickInputList.ts/QuickInputList/setFocusedElements
class QuickInputList:	setFocusedElements(items: IQuickPickItem[]) {
		this.list.setFocus(items
			.filter(item => this.elementsToIndexes.has(item))
			.map(item => this.elementsToIndexes.get(item)!));
		if (items.length > 0) {
			const focused = this.list.getFocus()[0];
			if (typeof focused === 'number') {
				this.list.reveal(focused);
			}
		}
	}