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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 create_manager(self, yosai, settings, session_attributes):
 """ Order of execution matters. The sac must be set before the cache_handler is instantiated so that the cache_handler's serialization manager instance registers the sac. """

        mgr_settings = SecurityManagerSettings(settings)
        attributes = mgr_settings.attributes

        realms = self._init_realms(settings, attributes['realms'])

        session_attributes = self._init_session_attributes(session_attributes, attributes)

        serialization_manager =\
            SerializationManager(session_attributes,
                                 serializer_scheme=attributes['serializer'])

        # the cache_handler doesn't initialize a cache_realm until it gets
        # a serialization manager, which is assigned within the SecurityManager
        cache_handler = self._init_cache_handler(settings,
                                                 attributes['cache_handler'],
                                                 serialization_manager)

        manager = mgr_settings.security_manager(yosai,
                                                settings,
                                                realms=realms,
                                                cache_handler=cache_handler,
                                                serialization_manager=serialization_manager)

        return manager