public void TestSetup()
        {
            _aviaService = Substitute.For<IAviaService>();
            _dpService = Substitute.For<IDpService>();
            _criteriaFactory = Substitute.For<ICriteriaFactory>();
            _decisionFactory = Substitute.For<IDecisionFactory>();

            _pricingManager = new PricingManager.PricingManager(_aviaService, _dpService, _criteriaFactory, _decisionFactory);
        }
        public PricingManager(IAviaService aviaService, IDpService dpService, ICriteriaFactory criteriaFactory, IDecisionFactory decisionFactory)
        {
            if(aviaService==null)
                throw new ArgumentNullException("aviaService");
            if (dpService == null)
                throw new ArgumentNullException("dpService");
            if (criteriaFactory == null)
                throw new ArgumentNullException("criteriaFactory");

            _aviaService = aviaService;
            _dpService = dpService;
            _criteriaFactory = criteriaFactory;
            _decisionFactory = decisionFactory;
        }