code: @Override
      public Response attachFile(String CorpNum, MgtKeyType KeyType,
                                 String MgtKey, String DisplayName, InputStream FileData)
              throws PopbillException {
          return attachFile(CorpNum, KeyType, MgtKey, DisplayName, FileData, null);
      }
docs: /* (non-Javadoc)
  @see com.popbill.api.TaxinvoiceService#attachFile(java.lang.String, com.popbill.api.taxinvoice.MgtKeyType, java.lang.String, java.lang.String, java.io.InputStream)