public async void Get_null_record()
        {
            var mock = new ServiceMockFacade <ILessonRepository>();

            mock.RepositoryMock.Setup(x => x.Get(It.IsAny <int>())).Returns(Task.FromResult <Lesson>(null));
            var service = new LessonService(mock.LoggerMock.Object,
                                            mock.RepositoryMock.Object,
                                            mock.ModelValidatorMockFactory.LessonModelValidatorMock.Object,
                                            mock.BOLMapperMockFactory.BOLLessonMapperMock,
                                            mock.DALMapperMockFactory.DALLessonMapperMock,
                                            mock.BOLMapperMockFactory.BOLLessonXStudentMapperMock,
                                            mock.DALMapperMockFactory.DALLessonXStudentMapperMock,
                                            mock.BOLMapperMockFactory.BOLLessonXTeacherMapperMock,
                                            mock.DALMapperMockFactory.DALLessonXTeacherMapperMock);

            ApiLessonResponseModel response = await service.Get(default(int));

            response.Should().BeNull();
            mock.RepositoryMock.Verify(x => x.Get(It.IsAny <int>()));
        }
        public async void TestGet()
        {
            ApiLessonResponseModel response = await this.Client.LessonGetAsync(1);

            response.Should().NotBeNull();
        }