I think the best way to integrate IEnforcer (rbac api) and ManagementEnforcer (management api) to a one IEnforcer is use Extension Method to implement it. Here are some reasons:

1. IEnforcer can be a simple and clean interface.
2. We can maintain the RBAC and Management API at different class, and we can easy to add new helper type API.
3. Follow the CARP desgin.

It will become a break change, we should change the protect field to Read-only property (also GetModel method can do it) and delete the InternalEnforcer, ManagementEnforcer and CoreEnforcer and convert them to a Enforcer class which only includes the API in InternalEnforcer and CoreEnforcer in now version).

Relate comment:
#55 (comment)