    def load_state_dict(self, training_state: Dict[str, Any]):
        """
        Loads each optimizer's `state_dict`.
        """
        for optimizer_key, optimizer in self.optimizers.items():
            optimizer.load_state_dict(training_state[f"{optimizer_key}_optimizer"])
Loads each optimizer's `state_dict`.
allennlp/training/optimizers.py