listeners.kt

    val listener = eventBus {
        on (javaClass<Started>()) signal { c -> println("job ${c.job} started")}
        on (javaClass<Failed>()) signal { f -> println("job failed: ${f.t.getMessage()}")}
        on (javaClass<Completed<Int>>()) signal { c -> println("job ${c.job} completed, result is ${c.result}")}
    }