public CalculationApp(IOffersReader offersReader, ICalculationsOutput calculationsOutput, IQuoteCalculator quoteCalculator) { if (null == offersReader) { throw new ArgumentNullException(nameof(offersReader)); } if (null == calculationsOutput) { throw new ArgumentNullException(nameof(calculationsOutput)); } if (null == quoteCalculator) { throw new ArgumentNullException(nameof(quoteCalculator)); } this._offersReader = offersReader; this._calculationsOutput = calculationsOutput; this._quoteCalculator = quoteCalculator; }