You mean passing an enum as config value, instead of passing a string? Hmm, is that really feasible? The config value is passed to the module as a JSON object, which usually means only text and numbers — but, hmm, there is a method `JsonObject.putValue(String fieldName, Object value)` that seems to make it possible to send an enum value, but then people would need to include mod-mongo-persistor on the classpath, in order to be able to configure it (so the enum becomes accessible at compilation time). Currently I think people don't need to add any additional dependencies in order to configure mod-mongo-persistor, is that really something it's okay to change?