Gets updater states.

        Parameters
        ----------
        dump_optimizer : bool, default False
            Whether to also save the optimizer itself. This would also save optimizer
            information such as learning rate and weight decay schedules.

def get_states(self, dump_optimizer=False):
        """Gets updater states.

        Parameters
        ----------
        dump_optimizer : bool, default False
            Whether to also save the optimizer itself. This would also save optimizer
            information such as learning rate and weight decay schedules.
        """
        return pickle.dumps((self.states, self.optimizer) if dump_optimizer else self.states)