public async Task CopyModel()
        {
            string endpoint        = TestEnvironment.Endpoint;
            string apiKey          = TestEnvironment.ApiKey;
            Uri    trainingFileUri = new Uri(TestEnvironment.BlobContainerSasUrl);
            string resourceId      = TestEnvironment.TargetResourceId;
            string resourceRegion  = TestEnvironment.TargetResourceRegion;

            #region Snippet:FormRecognizerSampleCreateCopySourceClient
            //@@ string endpoint = "<source_endpoint>";
            //@@ string apiKey = "<source_apiKey>";
            var sourcecredential = new AzureKeyCredential(apiKey);
            var sourceClient     = new FormTrainingClient(new Uri(endpoint), sourcecredential);
            #endregion

            // For the purpose of this sample, we are going to create a trained model to copy. Please note that
            // if you already have a model, this is not necessary.
            //@@ Uri trainingFileUri = <trainingFileUri>;
            TrainingOperation operation = await sourceClient.StartTrainingAsync(trainingFileUri, useTrainingLabels : false);

            Response <CustomFormModel> operationResponse = await operation.WaitForCompletionAsync();

            CustomFormModel model = operationResponse.Value;

            string modelId = model.ModelId;

            #region Snippet:FormRecognizerSampleCreateCopyTargetClient
            //@@ string endpoint = "<target_endpoint>";
            //@@ string apiKey = "<target_apiKey>";
            var targetCredential = new AzureKeyCredential(apiKey);
            var targetClient     = new FormTrainingClient(new Uri(endpoint), targetCredential);
            #endregion

            #region Snippet:FormRecognizerSampleGetCopyAuthorization
            //@@ string resourceId = "<resourceId>";
            //@@ string resourceRegion = "<region>";
            CopyAuthorization targetAuth = await targetClient.GetCopyAuthorizationAsync(resourceId, resourceRegion);

            #endregion

            #region Snippet:FormRecognizerSampleToJson
            string jsonTargetAuth = targetAuth.ToJson();
            #endregion

            #region Snippet:FormRecognizerSampleFromJson
            CopyAuthorization targetCopyAuth = CopyAuthorization.FromJson(jsonTargetAuth);
            #endregion

            #region Snippet:FormRecognizerSampleCopyModel
            //@@ string modelId = "<source_modelId>";
            CustomFormModelInfo newModel = await sourceClient.StartCopyModelAsync(modelId, targetCopyAuth).WaitForCompletionAsync();

            Console.WriteLine($"Original model ID => {modelId}");
            Console.WriteLine($"Copied model ID => {newModel.ModelId}");
            #endregion
        }