code: def keys(self):
          
          try:
              return self._metadata["fields"]
          except KeyError:
              if self.attached():
                  self._session.send()
              while self.attached() and "fields" not in self._metadata:
                  self._session.fetch()
              return self._metadata.get("fields")
docs: The keys for the records in this result.
  
          :returns: tuple of key names