A modern programming language that makes developers happier.

kotlinlang

It comes up a lot, *Immutable collections*.  You can block casting of `List` and other collection interfaces in Kotlin to their base type as shown by <@U0HKAGG4V> in an SO answer (<http://stackoverflow.com/a/37936456/3679676>) and now with a fuller version of that that blocks a variety of collection types, and anything they return from members that are also collections (i.e. `entrySet` from Map), released in Klutter  and mentioned here with more details <http://stackoverflow.com/a/38002121/3679676>