src/vs/workbench/contrib/tasks/browser/taskQuickPick.ts/TaskQuickPick/_doPickerFirstLevel
class TaskQuickPick:	private async _doPickerFirstLevel(picker: IQuickPick<ITaskTwoLevelQuickPickEntry>, taskQuickPickEntries: QuickPickInput<ITaskTwoLevelQuickPickEntry>[]): Promise<Task | ConfiguringTask | string | null | undefined> {
		picker.items = taskQuickPickEntries;
		const firstLevelPickerResult = await new Promise<ITaskTwoLevelQuickPickEntry | undefined | null>(resolve => {
			Event.once(picker.onDidAccept)(async () => {
				resolve(picker.selectedItems ? picker.selectedItems[0] : undefined);
			});
		});
		return firstLevelPickerResult?.task;
	}