public IEnumerable<Product> get_products_belonging_to(Department parent_department)
 {
     return Enumerable.Range(1, 100).Select(x => new Product
     {
         name = x.ToString("Product 0"),
         description = x.ToString("Description"),
         price =
                                                10.00m*x
     });
 }
 public IEnumerable<Department> get_departments_belonging_to(Department parent_department)
 {
     return Enumerable.Range(1, 100).Select(x => new Department {name = x.ToString("Sub Department 0")});
 }