public void GetAllUser()
        {
            //arrange
            IUserCollection userCollection = UserCollectionFactory.GetUserCollection();
            UserDTO         userDTO        = new UserDTO("GetAllUsersTest", "AddUserTestPassword");

            userCollection.AddUser(userDTO);

            //act
            List <UserDTO> userDTOs = userCollection.GetAllUsers();

            //assertt
            List <string> names = new List <string>();

            foreach (var user in userDTOs)
            {
                names.Add(user.Name);
            }
            bool contains = names.Contains(userDTO.Name);

            Assert.AreEqual(true, contains);
        }