def _load_child_state_models(self, load_meta_data):
        """Adds models for each child state of the state

        :param bool load_meta_data: Whether to load the meta data of the child state
        """
        self.states = {}
        # Create model for each child class
        child_states = self.state.states
        for child_state in child_states.values():
            # Create hierarchy
            model_class = get_state_model_class_for_state(child_state)
            if model_class is not None:
                self._add_model(self.states, child_state, model_class, child_state.state_id, load_meta_data)
            else:
                logger.error("Unknown state type '{type:s}'. Cannot create model.".format(type=type(child_state)))
Adds models for each child state of the state

        :param bool load_meta_data: Whether to load the meta data of the child state