def findCheckerFactory(authType):
    """
    Find the first checker factory that supports the given authType.
    """
    for factory in findCheckerFactories():
        if factory.authType == authType:
            return factory
    raise InvalidAuthType(authType)

    Find the first checker factory that supports the given authType.
    
stackoverflow/venv/lib/python3.6/site-packages/twisted/cred/strcred.py