public override int GetHashCode()
        {
            int hash = 1;

            if (S != 0D)
            {
                hash ^= S.GetHashCode();
            }
            if (Ds != 0D)
            {
                hash ^= Ds.GetHashCode();
            }
            if (Dds != 0D)
            {
                hash ^= Dds.GetHashCode();
            }
            return(hash);
        }