Coroutine parallelMap

suspend fun <A, B> Collection<A>.parallelMap(
    context: CoroutineContext = DefaultDispatcher,
    block: suspend (A) -> B
): Collection<B> {
    return map {
        // Use async to start a coroutine for each item
        async(context) {
            block(it)
        }
    }.map {
        // We now have a map of Deferred<T> so we await() each            
        it.await()
    }
}