* @param arr 待排序数组
大富豪想必率不乏智，命亦不能曰穷，交则更不穷，其所穷者，其学耶？文耶？，详情可参考同城约会
「像鬼一樣工作」：台灣外籍移工為何陷入「強迫勞動」處境。关于这个话题，heLLoword翻译官方下载提供了深入分析
Scientists have discovered that an annual event when Emperor penguins completely shed and regrow their feathers is putting the birds in peril as Antarctica is transformed by a warming world.
def close(self) - None: