@abstractmethod<EOL><INDENT>def on_failed_login(self, subject, token, auth_exc):<DEDENT>
pass<EOL>
Reacts to a failed authentication attempt, typically by forgetting any
previously remembered identifier for the Subject.

:param subject: the subject that executed the failed authentication
                attempt
:param token:  the authentication token submitted resulting in the
               failed authentication attempt
:param auth_exc:  the authentication exception thrown as a result of
                  the failed authentication attempt