Thanks for wanting to report an issue you've found in redis-py. Please delete this text and fill in the template below.
It is of course not always possible to reduce your code to a small test case, but it's highly appreciated to have as much data as possible. Thank you!

Version: What redis-py and what redis version is the issue happening on?

Platform: What platform / version? (For example Python 3.5.1 on Windows 7 / Ubuntu 15.10 / Azure)

Description: Description of your issue, stack traces from errors and code that reproduces the issue

The async version of Redis client takes credential_provider as argument while the get_credential() method is not an async method.

I think a better version should be

class CredentialProvider:
    """
    Credentials Provider.
    """

    async def get_credentials(self) -> Union[Tuple[str], Tuple[str, str]]:
        raise NotImplementedError("get_credentials must be implemented")