partial void DeleteStaff(Staff instance);
 partial void UpdateStaff(Staff instance);
		private void detach_Staffs(Staff entity)
		{
			this.SendPropertyChanging();
			entity.Department = null;
		}
 partial void InsertStaff(Staff instance);
		private void attach_Staffs(Staff entity)
		{
			this.SendPropertyChanging();
			entity.Department = this;
		}