At the moment we don't have a function to dynamically remove an adapter once it is registered. You can call `register_factory` with the same `from_protocol` and `to_protocol` (i.e., override the adapter). That simply adds it to the register. 

If the first adapter factory always creates an adapter, the second never gets called. If, because of conditional adaptation, the first one passes, the second one gets a chance of creating an adapter.