private async Task <IEnumerable <CurrencyInfo> > GetFilteredDataSet(string currency = null)
{
var data = await _currencyManager.GetData();
if (!string.IsNullOrEmpty(currency))
{
Console.WriteLine("Filtering by currency {0}", currency);
data = data.Where(c => c.Code.ToLower() == currency.ToLower());
}
return(data);
}