Yeah, you can't put it *inside* a for, it has to stand along like in my example above. It also hands your closure a variable that is the current count through the loop, e.g.,
```groovy
popsize.times { i ->
   // …
}
```
You can then use ```i``` in your closure and it will be 0, then 1, then 2, etc., incrementing once each new time through the loop.

Hope that helps.