private DependencyManager()
        {
            _adminDao   = new AdminDao();
            _adminLogic = new AdminLogic(_adminDao);

            _cityDao   = new CityDao();
            _cityLogic = new CityLogic(_cityDao);

            _skillDao   = new SkillDao();
            _skillLogic = new SkillLogic(_skillDao);

            _responseDao = new ResponseDao();

            _employeeDao   = new EmployeeDao();
            _employeeLogic = new EmployeeLogic(_employeeDao, _responseDao, _cityLogic, _skillLogic);

            _vacancyDao   = new VacancyDao();
            _vacancyLogic = new VacancyLogic(_vacancyDao, _skillLogic, _responseDao);

            _employerDao   = new EmployerDao();
            _employerLogic = new EmployerLogic(_employerDao, _cityLogic, _vacancyLogic);

            _hiringLogic = new HiringLogic(_vacancyLogic, _employeeLogic);

            _commonLogic = new CommonLogic(_adminDao, _employerDao, _employeeDao);
        }
 static EmployerRequestHandler()
 {
     _employerLogic = DependencyManager.Instance.EmployerLogic;
     _commonLogic   = DependencyManager.Instance.CommonLogic;
     _sha256        = new SHA256Cng();
 }