Symbol.asyncIterator
The Symbol.asyncIterator well-known symbol specifies the default AsyncIterator for an object. If this property is set on an object, it is an async iterable and can be used in a for await...of loop. The Symbol.asyncIterator symbol is a builtin symbol that is used to access an object's @@asyncIterator method.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/asyncIterator