I tried to update one entity in my client using breezejs library. After calling saveChanges(), it can actually save back in the server and fetched on the client. However, the server did not return the response back. The saveResult.entities is undefined and pop up an error for me. When I took a look at the docs, it mentions 'Some service APIs do not return information about every saved entity. If your server doesn't return such information, you should add the pre-save, cached entity to saveResult.entities yourself'. Could you please provide an example of how to do this?