private InvestmentVehicleBuilderForTests AddReturn(
            MonthYear monthYear,
            decimal returnValue,
            FeeType feeType)
        {
            var netSeries = _investmentVehicle.GetAllReturnSeries().FirstOrDefault(s => { return(s.FeeType == feeType); });

            if (netSeries == null)
            {
                netSeries = new MonthlyReturnSeries()
                {
                    FeeType = feeType
                };
                _investmentVehicle.AddReturnSeries(netSeries);
            }

            netSeries.AddReturn(monthYear, returnValue);

            return(this);
        }