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kotlinlang

Then, because you have `slots` missing from one object instead of empty `"slots": []` you must make the `slots` member nullable:

```
val slots: Set&lt;RuneSlot&gt;?
```

Or change your incoming JSON to provide an empty array instead of a missing element.

It is possible in Jackson 2.8.x I could change the Kotlin module to treat missing collections as empty collections, but in all history of Jackson this has not been the case.