@PreUpdate
    @PrePersist
    public void _clearEmptyGameTeams() {
        if (sides != null) {
            for (final Side side : sides.keySet()) {
                final GameSide gameSide = sides.get(side);
                if (gameSide != null) {
                    if (gameSide.getTeam() == null && gameSide.getScore() == null && gameSide.getSeed() == null) {
                        sides.put(side, null);
                    }
                }
            }
        }
    }