user-passes-test - validate that the user performing the search is allowed and the suggest_by param too.
Introduce a mandatory Model.Yaaac class that must define 2 attributes:
- user_passes_test : a class method returning True or False an taking a user as param.
- allows_suggest_by, which is a list of fields or methods allowed for suggestion (this is where you don't put 'raw_password' :-)