public void GetAllUsersTest() { //given Client client1 = new Client("John", "Bush", 1); Client client2 = new Client("Andrew", "Bush", 2); Client client3 = new Client("Peter", "Bush", 3); //when usersList.AddClients(client1, client2, client3); //then List <Client> allUsers = usersList.GetAllClients(); Assert.IsTrue(allUsers.Count == 3); Assert.IsTrue(allUsers.Contains(client1)); Assert.IsTrue(allUsers.Contains(client2)); Assert.IsTrue(allUsers.Contains(client3)); }