public async Task ExecuteAsync_WhenCalled_AssertNumberWasCalledOnCommand()
        {
            CommandHandler sut = CreateSut();

            Mock <IDeleteContactGroupCommand> commandMock = CreateCommandMock();
            await sut.ExecuteAsync(commandMock.Object);

            commandMock.Verify(m => m.Number, Times.Once);
        }
        public async Task ExecuteAsync_WhenCalled_AssertDeleteContactGroupAsyncWasCalledOnContactRepository()
        {
            CommandHandler sut = CreateSut();

            int number = _fixture.Create <int>();
            IDeleteContactGroupCommand command = CreateCommandMock(number).Object;
            await sut.ExecuteAsync(command);

            _contactRepositoryMock.Verify(m => m.DeleteContactGroupAsync(It.Is <int>(value => value == number)), Times.Once);
        }