Thanks for contributing @tandyjames!  I tried pulling out your workaround:

```ts
map<TArray>(iterator: (value: T, index: number, list: T[]) => TArray[], context?: any): _ChainOfArrays<TArray>;
```

And pasting in your commented code:

```ts
map<TArray>(iterator: _.ListIterator<T, TArray[]>, context?: any): _ChainOfArrays<TArray>;
```

And it seemed to work.  I only did a very quick test but all seemed okay....  What error did you see when you tried it?

BTW could you fix up some of the spacings to align with the other typings?