fun <A, B> Iterable<A>.parallelMap(context: CoroutineContext, f: suspend (A) -> B): List<B> = runBlocking {
    map { async(context) { f(it) } }.map { it.await() }
}

@OptIn(ExperimentalCoroutinesApi::class)
private val apiPool = Dispatchers.IO.limitedParallelism(10)

val results = foo.parallelMap(apiPool) { fetchStuffFromRestAPI(it.id) }

parallelMap

suspend

suspend fun <A, B> Iterable<A>.parallelMap(f: suspend (A) -> B): List<B> = coroutineScope {
    map { async { f(it) } }.map { it.await() }
}