result = extractor.classify_text(
What AIO Actually Means and Why It Matters
，详情可参考搜狗输入法
读研的日子，远比她想象中更辛苦，原典阅读艰涩，许多篇章往往要反复诵读十余遍，才能勉强领会其意，按照教学安排，每半个月向导师汇报一次，年轻同学可以熬夜讨论，她却要计算家庭与学业的时间分配。
In this case we’ll throw with a String and then the effect handler will give us Nothing back. In this case that’s a somewhat magical Nothing type that tells the compiler the function will never return, but it could be a real value, which we’ll see in later examples.