public void Can_Retrieve_Saved_Expense_From_Database()
        {
            using (var repo = new ExpenseRepository(_context))
            {
                _context.Staffs.Add(sampleEmployee);
                _context.SaveChanges();
                Expense staffExpense = new Expense
                                       (
                    "Unitest_Expenses",
                    30000,
                    sampleEmployee.Id
                                       );

                repo.Create(staffExpense);
                Expense savedExpense = repo.GetExpense(_context.Expenses.Single().Id);
                Assert.AreEqual("Unitest_Expenses", savedExpense.Description);
            }
        }