B2b External Service Exception
class B2bExternalServiceException : PortOneException, AttachB2bTaxInvoiceFileException, CancelB2bTaxInvoiceIssuanceException, CancelB2bTaxInvoiceRequestException, CreateB2bFileUploadUrlException, DeleteB2bTaxInvoiceAttachmentException, DeleteB2bTaxInvoiceException, DraftB2bTaxInvoiceException, GetB2bBulkTaxInvoiceException, GetB2bBusinessInfosException, GetB2bTaxInvoiceAttachmentsException, GetB2bTaxInvoiceException, GetB2bTaxInvoicePdfDownloadUrlException, GetB2bTaxInvoicePopupUrlException, GetB2bTaxInvoicePrintUrlException, GetB2bTaxInvoicesException, IssueB2bTaxInvoiceException, IssueB2bTaxInvoiceImmediatelyException, RefuseB2bTaxInvoiceRequestException, RequestB2bTaxInvoiceReverseIssuanceException, SendToNtsB2bTaxInvoiceException, UpdateB2bTaxInvoiceDraftException, requestB2bTaxInvoiceException
외부 서비스에서 에러가 발생한 경우