public async void LoadEnrolments(int studentId)
        {
            if (DesignerProperties.GetIsInDesignMode(
                new System.Windows.DependencyObject())) return;

            _repo = new EnrolmentRepo();
            Enrolments = new ObservableCollection<Enrolment>(await _repo.GetEnrolmentsAsync(studentId));
        }
        public async void LoadEnrolments(int studentId)
        {
            if (DesignerProperties.GetIsInDesignMode(
                    new System.Windows.DependencyObject()))
            {
                return;
            }

            _repo      = new EnrolmentRepo();
            Enrolments = new ObservableCollection <Enrolment>(await _repo.GetEnrolmentsAsync(studentId));
        }