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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 login(self, action, registry, **kwargs):
 """ Logs in to a Docker registry. :param action: Action configuration. :type action: dockermap.map.runner.ActionConfig :param registry: Name of the registry server to login to. :type registry: unicode | str :param kwargs: Additional keyword arguments to complement or override the configuration-based values. :type kwargs: dict """

        log.info("Logging into registry %s.", registry)
        login_kwargs = {'registry': registry}
        auth_config = action.client_config.auth_configs.get(registry)
        if auth_config:
            log.debug("Registry auth config for %s found.", registry)
            login_kwargs.update(auth_config)
            insecure_registry = kwargs.get('insecure_registry')
            if insecure_registry is not None:
                login_kwargs['insecure_registry'] = insecure_registry
        else:
            raise KeyError("No login information found for registry.", registry)
        update_kwargs(login_kwargs, kwargs)
        res = action.client.login(**login_kwargs)
        if res:
            log.debug("User %(username)s logged into %(registry)s.", login_kwargs)
            self._login_registries.add(registry)
        return res