public final UnaryCallable<UpdateWorkflowRequest, Operation> updateWorkflowCallable() {
    return stub.updateWorkflowCallable();
  }
Updates an existing workflow. Running this method has no impact on already running executions
of the workflow. A new revision of the workflow might be created as a result of a successful
update operation. In that case, the new revision is used in new workflow executions.

<p>Sample code:

<pre>{@code
// This snippet has been automatically generated and should be regarded as a code template only.
// It will require modifications to work:
// - It may require correct/in-range values for request initialization.
// - It may require specifying regional endpoints when creating the service client as shown in
// https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
try (WorkflowsClient workflowsClient = WorkflowsClient.create()) {
  UpdateWorkflowRequest request =
      UpdateWorkflowRequest.newBuilder()
          .setWorkflow(Workflow.newBuilder().build())
          .setUpdateMask(FieldMask.newBuilder().build())
          .build();
  ApiFuture<Operation> future = workflowsClient.updateWorkflowCallable().futureCall(request);
  // Do something.
  Operation response = future.get();
}
}</pre>
java-workflows/google-cloud-workflows/src/main/java/com/google/cloud/workflows/v1/WorkflowsClient.java