private void CallMethod_Del(string method)
        {
            MethodInfo minfo      = m_Type.GetType().GetMethod(method);
            ExternCall externCall = (ExternCall)Delegate.CreateDelegate(typeof(ExternCall), null, minfo);

            externCall();
        }
        /// <inheritdoc />
        public double GetSalesTax(GenericRequestModel grm)
        {
            //Retrieve price
            var price = GetTotalCost(grm);

            //Retrieve sales tax
            var taxRate = ExternCall.GetTaxRate(grm.CurrentUser.RegionCode);

            //Return value
            return(price * taxRate);
        }