src/vs/base/browser/ui/list/listWidget.ts/MouseController/onContextMenu
class MouseController:	private onContextMenu(e: IListContextMenuEvent<T>): void {
		if (isMonacoEditor(e.browserEvent.target as HTMLElement)) {
			return;
		}

		const focus = typeof e.index === 'undefined' ? [] : [e.index];
		this.list.setFocus(focus, e.browserEvent);
	}