public IEnumerable<City> GetCities(Nation nation)
        {
            var cityStrings = nationCity.Contents.Where(x => x.Item1 == nation.Name).Select(x => x.Item2);

            return cityStrings.Select(x =>
            {
                return new City()
                {
                    Name = x
                };
            })
            .OrderBy(x => x.Name);
        }
        public City GetCity(string searchCityName, Nation searchNation)
        {
            var raw = core.Cities.FirstOrDefault(x => x.Nation.Name == searchNation.Name
                 && x.Name.Contains(searchCityName));

            if (raw == null)
            {
                return null;
            }

            return new City()
            {
                Name = raw.Name,
                Nation = searchNation
            };
        }
 public IEnumerable<City> GetCities(Nation nation)
 {
     return mockService.GetCities(nation);
 }