/// <summary> /// Checks the invoice identifier. /// </summary> /// <returns></returns> public static string CheckInvoiceId(List <string> invoiceIds) { string uniqId = RandomHelpers.GetUniqueOrderInvoiceId(); if (invoiceIds != null) { againCheck: var check = invoiceIds.Contains(uniqId); if (check) { uniqId = RandomHelpers.GetUniqueOrderInvoiceId(); goto againCheck; } else { return(uniqId); } } else { return(uniqId); } }