public BuildParcelChain()
        {
            _rootChain = new InsuranceDepartment();
            IDepartmentChain dep2 = new MailDepartment();
            IDepartmentChain dep3 = new RegularDepartment();
            IDepartmentChain dep4 = new HeavyDepartment();

            _rootChain.SetNext(dep2);
            dep2.SetNext(dep3);
            dep3.SetNext(dep4);
        }
 public void SetNext(IDepartmentChain c)
 {
     _nextInChain = c;
 }