public void RepositoryTest_ContainsKeyFalse() { //Arrange var contactsDto = new List <ContactDto>() { new WorkDto() { TaxId = 1, Name = "Name", Address = "address1", Company = "Company", EmailAddress = "*****@*****.**", PhoneNumber = "000000000", Title = "Title", Url = "www.url.com" }, }; var repository = new ContactRepository(contactsDto); //Act var result = repository.ContainsKey(2); //Assert Assert.AreEqual(result, false); }