private void lstLectures_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            if (lstLectures.SelectedItems.Count != 1)
            {
                return;
            }
            var casted          = (Lecture)lstLectures.SelectedItems[0].Tag;
            var viewLectureForm = new ViewLectureForm(_serviceLocator, casted);

            viewLectureForm.ShowDialog();
        }
        private void btnStartLecture_Click(object sender, EventArgs e)
        {
            if (lstCourses.SelectedItems.Count != 1)
            {
                MessageBox.Show("Please Select a Course!");
                return;
            }
            var newLecture      = _coursesService.StartLecture(_selectedCourse.Id);
            var viewLectureForm = new ViewLectureForm(_serviceLocator, newLecture);

            viewLectureForm.ShowDialog();
        }