public async void CreateUser_Valid_Test()
        {
            //Arrange
            _adapterMock.Setup(r => r.Create(_user)).Returns(Task.FromResult(_user.Id));
            var userHandler = new UserHandler(_adapterMock.Object);

            //Act
            var returnedId = await userHandler.Create(_user);

            //Assert
            Assert.IsTrue(returnedId == _user.Id);
        }
        public async void CreateUser_Invalid_userInformationEmptyString_Test()
        {
            //Arrange
            var user = new User {Name = "", MetaData = ""};
            _adapterMock.Setup(r => r.Create(user));
            var userHandler = new UserHandler(_adapterMock.Object);

            //Act
            var result = await userHandler.Create(user);

            //Assert
            //Exception must be thrown
        }
        public async void CreateUser_Invalid_userIsNull_Test()
        {
            //Arrange
            _adapterMock.Setup(r => r.Create(null));
            var userHandler = new UserHandler(_adapterMock.Object);

            //Act
            var result = await userHandler.Create(null);

            //Assert
            //Exception must be thrown
        }