fun showUserOrders(username: String, password: String) = GlobalScope.launch(Dispatchers.Main) {
    val user = withContext(Dispatchers.Default) { login(username, password) }
    val orders = withContext(Dispatchers.Default) { fetchUserOrders(user.userId) }
    showUserOrders(orders)
}

suspend fun login(username: String, password: String) { }

suspend fun fetchUserOrders(userId: Long) { }