public override int GetHashCode()
        {
            var hashCode = 1398195996;

            hashCode = hashCode * -1521134295 + ra.GetHashCode();
            hashCode = hashCode * -1521134295 + RA.GetHashCode();
            hashCode = hashCode * -1521134295 + cod.GetHashCode();
            hashCode = hashCode * -1521134295 + Cod.GetHashCode();
            hashCode = hashCode * -1521134295 + nota.GetHashCode();
            hashCode = hashCode * -1521134295 + Nota.GetHashCode();
            hashCode = hashCode * -1521134295 + frequencia.GetHashCode();
            hashCode = hashCode * -1521134295 + Frequencia.GetHashCode();

            if (hashCode < 0)
            {
                hashCode = -hashCode;
            }

            return(hashCode);
        }