Obs group parents should not, themselves, have a value (see this thread). Until obs groups can be separated from obs (TRUNK-1858), we should at least prevent grouping obs (parent obs with members) from having a value.
In the ObsValidator
- Throw an APIException if an obs with members has any value filled in
In the Obs.java class:
- In the Obs.addMember method, check to make sure the current obs doesn't have any values. Throw an APIException if it does.