How can I get async behavior out of the Fluent SDK?

_From @awesley on June 23, 2017 19:25_

Hiya,

I'm creating VMs using the Fluent SDK. Here's a code snippet:

```
var vm = await this.azure

.VirtualMachines

.Define(vmName)

.WithRegion(region)

.WithExistingResourceGroup(resourceGroupName)

.WithExistingPrimaryNetwork(network)

.WithSubnet(subNetName)

.WithPrimaryPrivateIPAddressDynamic()

.WithoutPrimaryPublicIPAddress()

.WithWindowsCustomImage(image)

.WithAdminUsername(adminUserName)

.WithAdminPassword(adminPassword)

.WithSize(vmSize)

.WithNewStorageAccount(storageAccountName)

.WithTag(TagKeyNames.StorageAccountId, storageAccount.Id)

.CreateAsync();
```

This task does not complete until the machine is entirely provisioned and booting - a period of over ten minutes. That doesn't seem async to me. Is there something I am doing wrong? I want the call to return prior to the machine's availability.

For comparison, when provisioning a VM on Amazon EC2 returns nearly immediately, well before the machine is fully provisioned and booted.

I need from the call is the Id (`vm.Id`), the Primary Private IP (`vm.GetPrimaryNetworkInterface().PrimaryPrivateIP`), and the primary NIC Id (`vm.PrimaryNetworkInterfaceId`). I do not need the machine to be ready.

Thanks!

_Copied from original issue: Azure/azure-sdk-for-net#3411_

まず Fluent SDK の VM CreateAsync のプロビジョニングパスを追跡し、意図された完了セマンティクスについて issue の議論を確認します。マシンの準備が完了する前に、要求された VM ID、プライマリプライベート IP、NIC ID が利用可能かどうかを判断します。完了とは、それらの要件に一致するサポートされた戻りポイントを文書化または実装することです。

索引モデルが issue の本文から書いたものです。