private async Task <bool> FillPersonIdToState(ConcurrentDictionary <string, string> personIdToSateDic, List <Bill> bills, int[] rangeInfo) { foreach (Bill bill in bills.GetRange(rangeInfo[0], rangeInfo[1])) { Customer customer = await _customerApiService.GetCustomerAsync(bill.PersonId); string state = (customer == null ? STATE_FOR_NOT_REGISTERED_CUSTOMER : customer.State); personIdToSateDic.TryAdd(bill.PersonId, state); } return(true); }