runInAsync

fun <T> runInAsync(    scope: CoroutineScope,     context: CoroutineContext = EmptyCoroutineContext,     block: suspend CoroutineScope.() -> T): CompletableFuture<T>
fun <T> runInAsync(block: suspend CoroutineScope.() -> T): CompletableFuture<T>

执行一个异步函数,得到 CompletableFuture.