I would like to register a filter for CompassOperations. The filter would be called on save/create/delete operations with the user object as a parameter. The filter could then decide whether the user object is eligible for save/create/delete or not. This functionality could then be used for denying save/create/delete on unwanted objects. For example, I have a business object which contains sensitive data. I do not wish this sensitive data to be indexed. To achieve this, I would like to implement a filter interface found in the Compass library, and register an object of the implementation to CompassOperations.