/// <summary>
        /// DataGridCourses_UnloadingRow
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void DataGridCourses_UnloadingRow(object sender, DataGridRowEventArgs e)
        {
            Course course = e.Row.Item as Course;

            RemoveCouseFromBinding(course);
        }
 private bool BindingAlreadyExist(Course course, Student student)
 {
     return(Bindings.FirstOrDefault(b => b.StudentId == student.Id && b.CourseId == course.Id) == null ? false : true);
 }