public async Task <List <TradingInstrumentContract> > List([FromQuery] string tradingConditionId) { var data = string.IsNullOrWhiteSpace(tradingConditionId) ? await _tradingInstrumentsRepository.GetAsync() : await _tradingInstrumentsRepository.GetByTradingConditionAsync(tradingConditionId); return(data.Select(x => _convertService.Convert <ITradingInstrument, TradingInstrumentContract>(x)).ToList()); }