public static IList<Employee> InitEmployees()
        {
            IList<Employee> employees = new List<Employee>();
            Employee employee = new Employee() { Id = 1, Name = "Name1" };
            employee.Account = AccountsController.Accounts.Single(a => a.Id == 1);
            employees.Add(employee);

            Manager mananger = new Manager { Id = 2, Name = "Name2", Heads = 1 };
            mananger.DynamicProperties.Add("Level", 1);
            mananger.DynamicProperties.Add("Gender", Gender.Male);
            mananger.DynamicProperties.Add("PhoneNumbers", new List<string>() { "8621-8888-8888", "8610-6666-6666" });
            employees.Add(mananger);

            return employees;
        }
        public IHttpActionResult PutManager(int key, Manager employee)
        {
            Manager originalEmployee = Employees.OfType<Manager>().Single(e => e.Id == key);
            employee.Id = key;

            Employees.Remove(originalEmployee);
            Employees.Add(employee);
            return Ok(employee);
        }