@markstory I originally had unload() remove the mapped methods and finders, however that broke the ability to inject different objects into the registry via `BehaviorRegistry::set()` (since set() calls unload()). This is used in https://github.com/cakephp/cakephp/blob/3.0/tests/TestCase/ORM/BehaviorRegistryTest.php#L181 to inject a mock for example.

This way accomplishes the same task without losing the ability to inject a different object.