fun main (args: Array<String>) = runBlocking {
    println("current thread: ${Thread.currentThread().name}")

    //switch to default Dispatcher
    val result = withContext(Dispatchers.Default) {
        delay(500)
        println("Thread: ${Thread.currentThread().name}")
        100
    }

    println("result: $result")
    println("back on: ${Thread.currentThread().name}")
}
//prints the following
current thread: main
Thread: DefaultDispatcher-worker-1
result: 100
back on: main