def checkpoint_dir(self) -> pathlib.Path:
        """Get the checkpoint directory for this config."""
        if not self.exp_name:
            raise ValueError("--exp_name must be set")
        return (pathlib.Path(self.checkpoint_base_dir) / self.name / self.exp_name).resolve()
Get the checkpoint directory for this config.
policy/openpi/src/openpi/training/config.py