public override IEnumerable <Forecast> GetForecast(City city)
        {
            var forecast = _repository.FindForecast(city.CityID);

            if (forecast.Count() == 0)
            {
                forecast = _yrWebservice.GetForecast(city);
                _repository.AddForecast(forecast);
                _repository.Save();
            }
            else
            {
                foreach (Forecast item in forecast)
                {
                    if (item.NextUpdate < DateTime.Now)
                    {
                        _repository.DeleteForecast(forecast);
                        _repository.Save();

                        forecast = _yrWebservice.GetForecast(city);

                        _repository.AddForecast(forecast);
                        _repository.Save();
                        break;
                    }
                }
            }
            return(forecast);
        }