public bool Edit(Toplanti toplanti)
 {
     try
     {
         HttpClient client = new HttpClient();
         client.BaseAddress = new Uri(Base_URL);
         client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
         HttpResponseMessage response = client.PutAsJsonAsync("values/" + toplanti.Id, toplanti).Result;
         return(response.IsSuccessStatusCode);
     }
     catch
     {
         return(false);
     }
 }