def load(self, dir_name, epoch=0, name=None):
        """save model to dir

        Parameters
        ----------
        dir_name: str
            name of the directory
        epoch: int
        """
        name = name or self.name
        dir_name = os.path.join(dir_name, name)
        pre = os.path.join(dir_name, self.subclass_name)
        _, arg_params, aux_params = mx.model.load_checkpoint(pre, epoch)
        self.model.set_params(arg_params, aux_params, force_init=True)
save model to dir

        Parameters
        ----------
        dir_name: str
            name of the directory
        epoch: int
        
python/magent/builtin/mx_model/base.py