public async Task<List<Field>> GetFields(FilterOptionModel filter)
        {
			try{
            string url = String.Format(CultureInfo.InvariantCulture
               , "{0}/api/canchas", _urlPrefix);

            return await base.PostAsync<FilterOptionModel,List<Field>>(url,filter);
			}
			catch(Exception ex) {
				return new List<Field> ();
			}
        }
        /// <summary>
        /// Load Data From web api
        /// </summary>
        /// <returns></returns>
        public async Task GetFieldsFromApiAsync()
        {
            if (IsBusy) return;
            IsBusy = true;
            //var location = await DependencyService.Get<ILocationServiceSingleton>()
            //    .CalculatePositionAsync();

            var filter = new FilterOptionModel() { date = DateTime.Now };

            var collection= await CoreClient.FieldsService.GetFields(filter);
			if(collection!=null && collection.Any()) FieldsCollection = new ObservableCollection<Field>(collection);
            IsBusy = false;
        }