def validate_results(results):
    """
    Fill in any missing values.

    Args:
        results (dict): Output of the calculate_matchups()

    Returns:
        Updated results dictionary with all class combinations represented.

    """
    names = results.keys()
    for p1_type in names:
        for p2_type in names:
            if p2_type not in results[p1_type]:
                results[p1_type][p2_type] = {
                    "wins": 0,
                    "total": 0
                }
    return results