public async Task <HistorialReceta> Alta(HistorialReceta obj)
        {
            Token  token = App.TokenDatabase.Obtener();
            string Url   = Web;

            using (HttpClient client = new HttpClient())
                using (HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, Url))
                {
                    client.DefaultRequestHeaders.Add("Authorization", "Bearer " + token._AccessToken);
                    string json = JsonConvert.SerializeObject(obj);
                    using (StringContent stringContent = new StringContent(json, Encoding.UTF8, "application/json"))
                    {
                        request.Content = stringContent;

                        using (HttpResponseMessage response = await client
                                                              .SendAsync(request, HttpCompletionOption.ResponseHeadersRead)
                                                              .ConfigureAwait(false))
                        {
                            string JsonResult = response.Content.ReadAsStringAsync().Result;
                            try
                            {
                                HistorialReceta ContentResp = Deseralizar(JsonResult);
                                return(ContentResp);
                            }
                            catch (Exception)
                            {
                                return(null);
                            }
                        }
                    }
                }
        }
        public async Task <HistorialReceta> Obtener(HistorialReceta obj)
        {
            Token  token = App.TokenDatabase.Obtener();
            string Url   = Web + obj._Email + "," + obj._IdHistorialReceta;

            HttpClient client = new HttpClient();

            client.DefaultRequestHeaders.Add("Authorization", "Bearer " + token._AccessToken);

            using (HttpResponseMessage response = await client.GetAsync(Url))
            {
                string JsonResult = response.Content.ReadAsStringAsync().Result;
                try
                {
                    HistorialReceta ContentResp = Deseralizar(JsonResult);
                    return(ContentResp);
                }
                catch (Exception)
                {
                    return(null);
                }
            }
        }
        private HistorialReceta Deseralizar(string jsonResult)
        {
            HistorialReceta p = JsonConvert.DeserializeObject <HistorialReceta>(jsonResult);

            return(p);
        }