public double Substract(double A, double B)
        {
            (bool isAuth, string User) = SecurityValidation.IsAuth(OperationContext.Current.ServiceSecurityContext);
            var C = A - B;

            Console.WriteLine("{0} {1} {2} = {3}", A, nameof(Substract), B, C);
            return(C);
        }
        public double Action(Inputs A)
        {
            (bool isAuth, string User) = SecurityValidation.IsAuth(OperationContext.Current.ServiceSecurityContext);
            switch (A.Operation)
            {
            case Inputs.OperationEnum.Addition:
                return(Add(A.A, A.B));

            case Inputs.OperationEnum.Substraction:
                return(Substract(A.A, A.B));

            case Inputs.OperationEnum.Multiplication:
                return(multiply(A.A, A.B));

            default:
                throw new NotImplementedException();
            }
        }