public void ExportStudents_Test()
        {
            //Arrange
            StudentPathProviderMock.Setup(x => x.GetPathToDownloadFrom())
            .Returns("D:\\master an 2\\css\\c\\students.csv");
            var controller = new StudentController(StudentServiceMock.Object,
                                                   CollegeRulesMock.Object,
                                                   StudentPathProviderMock.Object)
            {
                Request       = new HttpRequestMessage(),
                Configuration = new HttpConfiguration()
            };

            //Act
            var result = controller.DownloadDocument();

            //Assert
            var resultHeaders = result.Content.Headers;

            Assert.IsInstanceOfType(result, typeof(HttpResponseMessage));
            Assert.IsInstanceOfType(result.Content, typeof(StreamContent));
            Assert.IsInstanceOfType(resultHeaders.ContentDisposition, typeof(ContentDispositionHeaderValue));
            Assert.IsInstanceOfType(resultHeaders.ContentType, typeof(MediaTypeHeaderValue));

            Assert.AreEqual(resultHeaders.ContentDisposition, new ContentDispositionHeaderValue("attachment")
            {
                FileName = "Students.csv"
            });
            Assert.AreEqual(resultHeaders.ContentType, new MediaTypeHeaderValue("application/octet-stream"));
        }