public async Task ContactAccountsAsync_WhenCalled_ReturnsOkObjectResultWhereValueIsContactAccountCollectionModelContainingAllContactAccounts()
        {
            IList <IContactAccount>   contactAccounts          = _fixture.CreateMany <IContactAccount>(_random.Next(5, 10)).ToList();
            IContactAccountCollection contactAccountCollection = _fixture.BuildContactAccountCollectionMock(contactAccountCollection: contactAccounts).Object;
            Controller sut = CreateSut(contactAccountCollection);

            OkObjectResult result = (OkObjectResult)(await sut.ContactAccountsAsync(_fixture.Create <int>())).Result;

            ContactAccountCollectionModel contactAccountCollectionModel = (ContactAccountCollectionModel)result.Value;

            Assert.That(contactAccountCollectionModel, Is.Not.Null);
            Assert.That(contactAccountCollectionModel.Count, Is.EqualTo(contactAccounts.Count));
            Assert.That(contactAccountCollectionModel.All(contactAccountModel => contactAccounts.SingleOrDefault(contactAccount => string.CompareOrdinal(contactAccountModel.AccountNumber, contactAccount.AccountNumber) == 0) != null), Is.True);
        }