public async Task CalculateAnnualCostsAsync(Employee employee)
        {
            var rules = await _ruleRepository.GetAllRules();

            _ruleEngine.Start(employee);

            foreach (var rule in rules)
            {
                _ruleEngine.SetRule(rule);
                _ruleEngine.ApplyRule();
            }

            var benefitCost = _ruleEngine.End();

            employee.AnnualSalary = (employee.CompensationRate * _numPayPeriods);
            employee.AnnualCost   = employee.AnnualSalary - benefitCost;
        }