src/vs/base/browser/ui/list/listWidget.ts/KeyboardController/onDownArrow
class KeyboardController:	private onDownArrow(e: StandardKeyboardEvent): void {
		e.preventDefault();
		e.stopPropagation();
		this.list.focusNext(1, false, e.browserEvent);
		const el = this.list.getFocus()[0];
		this.list.setAnchor(el);
		this.list.reveal(el);
		this.view.domNode.focus();
	}