public async Task AddingPersonsAddsAllPersons()
        {
            List <Person> personsToAdd = new List <Person>()
            {
                new Person
                {
                    FirstName = "John",
                    LastName  = "Doe"
                },
                new Person
                {
                    FirstName = "Mary",
                    LastName  = "Shelly"
                },
                new Person
                {
                    FirstName = "Patrick",
                    LastName  = "Bateman"
                }
            };

            List <Person> listOfAddedPersons = GetValueFromOkObjectResult <List <Person> >(await _personController.AddPersons(personsToAdd) as OkObjectResult);

            Assert.IsTrue(personsToAdd.Count == listOfAddedPersons.Count);

            foreach (Person p in personsToAdd)
            {
                Assert.IsTrue(listOfAddedPersons.Contains(p));
            }

            foreach (Person p in listOfAddedPersons)
            {
                await _personController.DeletePerson(p.Id);
            }
        }