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kotlinlang

Hi folks. Wouldn't it be possible for the the SetK, MapK or any other data structure return itself from a map(), instead of just `List&lt;A&gt;`? I know it is impossible in vanilla Kotlin because it doesn't have support Higher Kinded Types. Something like:
```
public inline fun &lt;F: Iterable, T, R&gt; F&lt;T&gt;.map(transform: (T) -&gt; R): F&lt;R&gt; 
```
Would be impossible. But what about use Arrow and get this:
```
public inline fun &lt;F: ForIterableK, T, R&gt; Kind&lt;F, T&gt;.mapK(transform: (T) -&gt; R): Kind&lt;F, R&gt; 
```
That would allow set.k.mapK { } to return a SetK, instead of a `List`.
Maybe if we have a interface like:
```
class ForSetK : ForIterableK private constructor() { companion object }
```

I don't understand how the `ForSetK` gets generated, but would it be possible for it to implement `Iterable`?