def METHOD_NAME(target_type: TargetType) -> str:
    """
    Converts a target type into a boolean string as expected by TyDi eval.
    """
    if target_type == TargetType.YES:
        return 'yes'
    elif target_type == TargetType.NO:
        return 'no'
    elif target_type == TargetType.NO_ANSWER:
        return 'none'
    else:
        raise NotImplementedError(f"Unexpected target type for tydi bool string conversion: {target_type}")