更新和删除不使用Google Cloud Endpoints

I have a class, Student and the generated Endpoint class for it. ListStudents and insertStudents methods work without any problems, but update and remove don't cause any change in the datastore. The methods don't throw any errors and the call returns, but no changes are made. My endpoints code is mostly the code generated by google plugin for eclipse:I have a class, Student and the generated Endpo