we can use the exists to substitute k with anything we want.
For multiple readers
，更多细节参见搜狗输入法
（四）强行冲闯公安机关设置的警戒带、警戒区或者检查点的。。谷歌是该领域的重要参考
They also had to make sure the button worked no matter how many times someone pressed it. “A lot of the feedback we got was that the function just isn’t triggering after several hundred or several thousand times, it’s failing,” he adds. The function department even rigged up a robot to simulate pushing the shutter button tens of thousands of times — one which, I’m unreasonably pleased to say, uses Lego to test Lego:
Кадр: @Bernie529 / Reddit