code: def getStageInfo(self, stageId):
          
          stage = self._jtracker.getStageInfo(stageId)
          if stage is not None:
              # TODO: fetch them in batch for better performance
              attrs = [getattr(stage, f)() for f in SparkStageInfo._fields[1:]]
              return SparkStageInfo(stageId, *attrs)
docs: Returns a :class:`SparkStageInfo` object, or None if the stage
          info could not be found or was garbage collected.