expect(iterable).toEqual([1, 2, 3])?

Why doesn't the following pass?
```JavaScript
function* iterable() {
  yield 1;
  yield 2;
  yield 3;
}
expect(iterable()).toEqual([1, 2, 3]);
```

I get:
```
Expected: [1, 2, 3]
Received: {}
```