/// <exception cref="ArgumentNullException"><paramref name="entity"/> is <see langword="null" />.</exception>
        public void Add(Department entity)
        {
            if(entity == null)
                throw new ArgumentNullException("entity");

            _departmentRepository.Insert(entity);
        }
 /// <exception cref="ArgumentNullException"><paramref name="entity"/> is <see langword="null" />.</exception>
 public void Update(Department entity)
 {
     _departmentRepository.Update(entity);
 }