If you are trying to add a duplicate entry under class of service then the existing configuration will be flushed and the new configuration will be saved.
Which should be altered and should throw a warning message "Already there is an entry with the same name." and deny the user to add duplicate entry.
Steps to reproduce:
1. Add a COS entry with "COS Name - test" and do some configuration.
2.Try to add another COS entry with "COS Name - test" and leave all the configurations empty.
3.Click on submit and open the "test" COS. The configurations done in step one will be flushed and all the options will be in default.