I can only speak for the Flask client as that is what I'm using. It would be great if the oauth.register(...) method had an oauth.remove(client_name).

Is your feature request related to a problem? Please describe.
I wanted to write a test for something and it involved registering an oauth2 (flask) client for testing purposes. After the tests complete, I want a clean way to remove that testing client from the oauth object, but I cannot see a way to do this.

Without it, running the test poses the following issues. (1) If I create the client in my test with a fixed name (e.g. 'Test Client'), it will return the first client from the oauth registry for all subsequent tests, instead of creating a new client each time. But if I create the client with a unique name for each test (e.g. 'Test Client 1', 'Test Cleint 2', ...), the oauth registry will grow for as many clients are registered until the server restarts. Obviously the latter is the expected behaviour, but a .remove_client method seems missing.

Describe the solution you'd like
Just like with oauth.register(...), maybe something like oauth.remove_client(client_name) would be nice. For example, in the https://github.com/lepture/authlib/blob/master/authlib/integrations/base_client/registry.py, we could add a new method:

def remove(self, client_name):
    if client_name not in self._registry:
        raise KeyError(f"Client {client_name} not found in registry.")

    if client_name not in self._clients:
        raise KeyError(f"Client {client_name} not found in registry.")

    del self._registry[client_name]
    del self._clients[client_name]

But I am not sure if this is sufficient or if it overlooks other issues.

Describe alternatives you've considered
As far as I can tell, we might be able to do this by simply editing the internal oauth._clients and oauth._registry dictionaries. For example del oauth._clients[my_test_client_name]; del oauth._registry[my_test_client_name] but I don't know if this fully accomplishes the goal. It definitely doesn't feel nice.