private async void UpdateCourse()
        {
            var course = await GetCourseItems();

            foreach (var item in course)
            {
                CourseListItems.Add(item);
            }
        }
        private async void GetCourses()
        {
            var allSections = await _courseServices.GetAllSections();

            foreach (var section in allSections)
            {
                CourseListItems.Add(
                    new AddStudentCourseListItemViewModel
                {
                    SectionId    = section.Id,
                    CourseCode   = section.Course.CourseCode,
                    Name         = section.Course.CourseName,
                    LecturerName = section.Lecturer.User.Name,
                    IsSelected   = false
                });
            }
        }