@SinceMirai("0.29.0") @JvmName("selectMessages1") suspend inline fun <reified T : ContactMessage> T.selectMessagesUnit(timeoutMillis: Long = -1, filterContext: Boolean = true, crossinline selectBuilder: MessageSelectBuilderUnit<T, Unit>.() -> Unit): Unit
selectMessages 的 Unit 返回值捷径 (由于 Kotlin 无法推断 Unit 类型)