code: def _add_full_message(gelf_dict, record):
          
          # if a traceback exists add it to the log as the full_message field
          full_message = None
          # format exception information if present
          if record.exc_info:
              full_message = '\n'.join(
                  traceback.format_exception(*record.exc_info))
          # use pre-formatted exception information in cases where the primary
          # exception information was removed, eg. for LogRecord serialization
          if record.exc_text:
              full_message = record.exc_text
          if full_message:
              gelf_dict["full_message"] = full_message
docs: Add the ``full_message`` field to the ``gelf_dict`` if any
          traceback information exists within the logging record
  
          :param gelf_dict: dictionary representation of a GELF log.
          :type gelf_dict: dict
  
          :param record: :class:`logging.LogRecord` to extract a full
              logging message from to insert into the given ``gelf_dict``.
          :type record: logging.LogRecord