public When_Opportunity_Controller_Delete_Referral()
        {
            var config = new MapperConfiguration(c => c.AddMaps(typeof(CheckAnswersDtoMapper).Assembly));
            var mapper = new Mapper(config);

            _opportunityService = Substitute.For <IOpportunityService>();

            var opportunityController = new OpportunityController(_opportunityService, mapper);
            var controllerWithClaims  = new ClaimsBuilder <OpportunityController>(opportunityController)
                                        .AddUserName("CreatedBy")
                                        .Build();

            _result = controllerWithClaims.DeleteReferralAsync(ReferralIdToDelete, OpportunityItemId).GetAwaiter().GetResult();
        }