public void ExportTest()
        {
            var productsStub = new List <FullProductDTO>()
            {
                new FullProductDTO()
                {
                    Id = 1, Code = "123", Name = "Cheese", Price = 100m
                },
                new FullProductDTO()
                {
                    Id = 24, Code = "321", Name = "Bread", Price = 23m
                },
            };
            var productServiceMoq = new Mock <IProductService>();

            productServiceMoq.Setup(x => x.Get()).Returns(productsStub);
            var exportService = new DataExporter(productServiceMoq.Object);
            var package       = exportService.GetPackage();
            var ws            = package.Workbook.Worksheets["Products"];

            Assert.NotNull(ws);

            foreach (var p in productsStub)
            {
                var row = productsStub.IndexOf(p) + 2;
                Assert.Equal(ws.Cells[row, 1].GetValue <string>(), p.Id.ToString());
                Assert.Equal(ws.Cells[row, 2].GetValue <string>(), p.Code.ToString());
                Assert.Equal(ws.Cells[row, 3].GetValue <string>(), p.Name.ToString());
                Assert.Equal(ws.Cells[row, 4].GetValue <string>(), p.Price.ToString());
            }
            package.Dispose();
        }