@Override
    public int hashCode() {
        int result = minimumValue != null ? minimumValue.hashCode() : 0;
        result = 31 * result + (maximumValue != null ? maximumValue.hashCode() : 0);
        result = 31 * result + (averageValue != null ? averageValue.hashCode() : 0);
        result = 31 * result + (singleValue != null ? singleValue.hashCode() : 0);
        return result;
    }