I create a new object that should be stored on the server:
[self.dataSource addToFolderDocumentItems: aNewObject];
where self.dataSource is an instance of a class generated by odatagen.
There is a bug on the server side - an exception is thrown during saving the new object. As a result, an "Internal server error" response is sent to the client application. But the saveChanges method returns correctly, so the client application
doesn't know that data hasn't been saved. I suggest that saveChanges method throw an exception if it receives an error from server.