public void GetAllExpensesTest()
        {
            var expense1 = GetNewMockExpense(collaborator.CollaboratorId, expenseStory.ExpenseStoryId);
            var expense2 = GetNewMockExpense(collaborator.CollaboratorId, expenseStory.ExpenseStoryId);
            var expense3 = GetNewMockExpense(collaborator.CollaboratorId, expenseStory.ExpenseStoryId);

            var expectedExpenseCount = 3;

            expenseManager.AddExpense(expense1);
            expenseManager.AddExpense(expense2);
            expenseManager.AddExpense(expense3);

            var allExpenses = expenseManager.GetAllExpenses(expenseStory.ExpenseStoryId);

            Assert.IsNotNull(allExpenses);
            Assert.AreEqual(expectedExpenseCount, allExpenses.Count());
        }