public void GetAllElements_RequestOfCollection_CollectionIsNotNull()
        {
            var mock = new Mock <IUnitOfWork>();

            mock.Setup(a => a.Subscribs.GetAllElements()).Returns(new List <Subscribe>());
            var service = new SubscribeService(mock.Object);

            var result = service.GetAllElements() as IEnumerable <SubscribeDTO>;

            Assert.IsNotNull(result);
        }