Alaksiej Ščarbaty

Add Kotlin contracts to exposed Kotlin API

4

## Overview Resolves #1866. Introduced `assertNull`, `assertNotNull` and `assertInstanceOf` methods. Introduced contracts for `assertNull`, `assertNotNull`, `assertThrows` and `assertDoesNotThrow` methods --- I hereby agree to the terms of the [JUnit Contributor...

Add description to JobConfig

22

Added description to a JobConfig according to the following issue: https://github.com/hazelcast/hazelcast/issues/20510