public async Task <IActionResult> OnPostAsync(Guid id)
        {
            var instructor = await _instructorRepository.GetInstructorWithChildrenAsync(id);

            //TODO
            //var departments = await _departmentRepository.GetDepartmentsFromInstructor(id);

            //foreach (var d in departments)
            //{
            //    d.DepartmentChairId = null;
            //    await _departmentRepository.UpdateAsync(d);
            //}

            await _instructorRepository.DeleteAsync(instructor);

            return(RedirectToPage("./Index"));
        }