public async Task GetPublicCurrencies() { // Public currencies List <TTCurrency> publicCurrencies; if (string.IsNullOrEmpty(PublicCurrenciesFilter)) { publicCurrencies = await _client.GetPublicAllCurrenciesAsync(); } else { publicCurrencies = await _client.GetPublicCurrencyAsync(PublicCurrenciesFilter); } PublicCurrencies = publicCurrencies != null ? new ObservableCollection <TTCurrency>(publicCurrencies) : null; }