public async Task <decimal> ConvertAsync(string fromAsset, string toAsset, decimal amount)
{
if (fromAsset == toAsset)
{
return(amount);
}
var currencyRate = await _currencyRateService.GetByIdAsync(fromAsset, toAsset);
if (currencyRate == null)
{
throw new EntityNotFoundException();
}
return(amount * currencyRate.Rate);
}