2. When received the `CreateCollection` request, `Proxy` would wrap this request into `CreateCollectionTask`, and pushes this task into `DdTaskQueue` queue. After that, `Proxy` would call `WaitToFinish` method to wait until the task is finished.
2. When receiving the `CreateCollection` request, `Proxy` would wrap this request into `CreateCollectionTask`, and pushes this task into `DdTaskQueue` queue. After that, `Proxy` would call `WaitToFinish` method to wait until the task is finished.