private static void GetTest()
        {
            CoursesClient client = new CoursesClient();

            List <Course> test = client.GetCourses();

            test.ForEach(Console.WriteLine);
        }
        private static void PostTest()
        {
            CoursesClient client = new CoursesClient();

            Course result = client.PostCourse(new Course()
            {
                Name = "Java3"
            });


            Console.WriteLine(result);
        }
        private static void PutTest()
        {
            CoursesClient client = new CoursesClient();

            Course result = client.UpdateProduct(new Course()
            {
                Id   = 670,
                Name = "Java3"
            });


            Console.WriteLine(result);
        }
        private static void DeleteTest()
        {
            CoursesClient client = new CoursesClient();

            client.DeleteCourse(670);
        }