def METHOD_NAME(trial: Trial, scores: list[float]) -> None:
    """A function to report cross-validation scores of a trial.
    This function should be called within the objective function to report the cross-validation
    scores. The reported scores are used to evaluate the statistical error for termination
    judgement.
    Args:
        trial:
            A :class:`~optuna.trial.Trial` object to report the cross-validation scores.
        scores:
            The cross-validation scores of the trial.
    """
    if len(scores) <= 1:
        raise ValueError("The length of `scores` is expected to be greater than one.")
    trial.storage.set_trial_system_attr(trial._trial_id, _CROSS_VALIDATION_SCORES_KEY, scores)