/// <summary>Snippet for UpdateWorkflow</summary>
        public void UpdateWorkflow()
        {
            // Snippet: UpdateWorkflow(Workflow, FieldMask, CallSettings)
            // Create client
            WorkflowsClient workflowsClient = WorkflowsClient.Create();
            // Initialize request argument(s)
            Workflow  workflow   = new Workflow();
            FieldMask updateMask = new FieldMask();
            // Make the request
            Operation <Workflow, OperationMetadata> response = workflowsClient.UpdateWorkflow(workflow, updateMask);

            // Poll until the returned long-running operation is complete
            Operation <Workflow, OperationMetadata> completedResponse = response.PollUntilCompleted();
            // Retrieve the operation result
            Workflow result = completedResponse.Result;

            // Or get the name of the operation
            string operationName = response.Name;
            // This name can be stored, then the long-running operation retrieved later by name
            Operation <Workflow, OperationMetadata> retrievedResponse = workflowsClient.PollOnceUpdateWorkflow(operationName);

            // Check if the retrieved long-running operation has completed
            if (retrievedResponse.IsCompleted)
            {
                // If it has completed, then access the result
                Workflow retrievedResult = retrievedResponse.Result;
            }
            // End snippet
        }