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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def on_successful_login(self, subject, authc_token, account_id):
 """ Reacts to the successful login attempt by first always forgetting any previously stored identity. Then if the authc_token is a ``RememberMe`` type of token, the associated identity will be remembered for later retrieval during a new user session. :param subject: the subject whose identifying attributes are being remembered :param authc_token: the token that resulted in a successful authentication attempt :param account_id: id of authenticated account """

        # always clear any previous identity:
        self.forget_identity(subject)

        # now save the new identity:
        if authc_token.is_remember_me:
            self.remember_identity(subject, authc_token, account_id)
        else:
            msg = ("AuthenticationToken did not indicate that RememberMe is "
                   "requested.  RememberMe functionality will not be executed "
                   "for corresponding account.")
            logger.debug(msg)