static readonly HttpClient httpClient = new HttpClient();
        private static readonly MeetingManager _singleton = new MeetingManager();
        private Models.Environment _currentEnv;

        public static MeetingManager SharedInstance()
        {
            return _singleton;
        }

        private MeetingManager()
        {
            //httpClient = new HttpClient();
            httpClient.BaseAddress = new Uri("http://192.168.100.5:3002/api/");
            // We want the response to be JSON.
            httpClient.DefaultRequestHeaders.Accept.Clear();
            httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        }

        public async Task<List<Meeting>> GetAllMeetingsV2(Action<IEnumerable<Meeting>> callback = null)
        {
            var meetings = new List<Meeting>();
            var currentEnvId = UserManager.SharedInstance().GetCurrentEnvironment().Id;
            var currentUserId = UserManager.SharedInstance().GetCurrentSession().User.Id;
            int page = 1, totalPages = 0;
            do
            {
                if (CrossConnectivity.Current.IsConnected)
                {
                    object data = new
                    {
                        idEnvironment = currentEnvId,
                        idUser = currentUserId,
                        page
                    };
                    var request = new HttpRequestMessage(HttpMethod.Post, "Meetings/getAllMeetingsV2")
                    {
                        Content = new StringContent(JsonConvert.SerializeObject(data), Encoding.UTF8, "application/json")
                    };
                    //HttpResponseMessage response = await httpClient.SendAsync(request).ConfigureAwait(false);
                    using (HttpResponseMessage response = await httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead).ConfigureAwait(false))
                    {
                        if (response.IsSuccessStatusCode) // response.EnsureSuccessStatusCode()
                        {
                            using (Stream s = await response.Content.ReadAsStreamAsync().ConfigureAwait(false))
                            using (StreamReader sr = new StreamReader(s))
                            using (JsonReader reader = new JsonTextReader(sr))
                            {
                                JsonSerializer serializer = new JsonSerializer();

                                // read the json from a stream
                                // json size doesn't matter because only a small piece is read at a time from the HTTP request
                                var result = serializer.Deserialize<PagedResult<Meeting>>(reader);
                                //}

                                //if (response.IsSuccessStatusCode)
                                //{
                                //string jsonString = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
                                //var result = JsonConvert.DeserializeObject<PagedResult<Meeting>>(jsonString);
                                if (result != null)
                                {
                                    if (result.Items != null/*result.Items.Any()*/)
                                    {
                                        //App.Database.SaveEntities(meetings, true).DoNotWait();

                                        // Build the full list to return later after the loop.
                                        meetings.AddRange(result.Items.ToList());

                                        // Run the callback method, passing the current page of data from the API.
                                        callback?.Invoke(result.Items);
                                    }

                                    // Get values for the next page
                                    page = result.Pagination.Page + 1;
                                    totalPages = result.Pagination.TotalPages;
                                }
                                else // result == null
                                {
                                    // End loop if we get an error response.
                                    totalPages = 0;
                                    //TODO: Load from local DB
                                }
                            }
                        }
                        else
                        {
                            // End loop if we get an error response.
                            totalPages = 0;
                            //TODO: Load from local DB
                        }
                    }
                }
                else
                {
                    // End loop if we get an error response.
                    totalPages = 0;
                    //TODO: Load from local DB
                }
            }
            while (page <= totalPages);
            return meetings;
        }