I thought I had missed something there, but it looks like it's just a bunch of utility methods to reinterpret integers and convert them to longs (etc.)?
Kotlin, on the other hand, recently added actual unsigned types[0] – taking up the same number of bits as the corresponding signed type, supporting the normal mathematical operators, and preventing unintended mixups with signed types.
[0] https://kotlinlang.org/docs/reference/basic-types.html#unsig...