public async static Task <List <Advertisement> > GetAdvertisements(string mobile)
        {
            List <Advertisement> advertisements = new List <Advertisement>();

            var url = AdvertisementRoot.GenerateUserURL(mobile);

            using (HttpClient client = new HttpClient())
            {
                var response = await client.GetAsync(url);

                var json = await response.Content.ReadAsStringAsync();

                var advList = JsonConvert.DeserializeObject <Advertisement[]>(json);

                advertisements = advList.ToList <Advertisement>();
            }

            return(advertisements);
        }
        public async static Task <List <Advertisement> > GetAdvertisements(double latitude, double longitude)
        {
            List <Advertisement> advertisements = new List <Advertisement>();

            var url = AdvertisementRoot.GenerateURL(latitude, longitude);

            using (HttpClient client = new HttpClient())
            {
                var response = await client.GetAsync(url);

                var json = await response.Content.ReadAsStringAsync();

                var advList = JsonConvert.DeserializeObject <Advertisement[]>(json);

                advertisements = advList.ToList <Advertisement>();
                //advertisements.AddRange(advList);
            }

            return(advertisements);
        }