src/vs/base/parts/quickinput/browser/quickInputList.ts/QuickInputAccessibilityProvider/isChecked
class QuickInputAccessibilityProvider:	isChecked(element: ListElement) {
		if (!element.hasCheckbox) {
			return undefined;
		}

		return {
			value: element.checked,
			onDidChange: element.onChecked
		};
	}