為什么 Symbol.asyncIterator 不工作？const obj = {  async *[Symbol.asyncIterator] () {    yield 10;    yield 100;    yield 1000;  },};for (const val of obj) {  console.log(obj);}錯(cuò)誤：類型錯(cuò)誤：obj 不可迭代for await (const val of obj) {  console.log(obj);}error: SyntaxError: for await (... of ...) 僅在異步函數(shù)和異步生成器中有效(async() => {  for await (const val of obj) {    console.log(val);  }})()error: SyntaxError: for await (... of ...) 僅在異步函數(shù)和異步生成器中有效