code: def bestModelInSprint(self, sprintIdx):
      
      # Get all the swarms in this sprint
      swarms = self.getAllSwarms(sprintIdx)
  
      # Get the best model and score from each swarm
      bestModelId = None
      bestErrScore = numpy.inf
      for swarmId in swarms:
        (modelId, errScore) = self._hsObj._resultsDB.bestModelIdAndErrScore(swarmId)
        if errScore < bestErrScore:
          bestModelId = modelId
          bestErrScore = errScore
  
      return (bestModelId, bestErrScore)
docs: Return the best model ID and it's errScore from the given sprint,
      which may still be in progress. This returns the best score from all models
      in the sprint which have matured so far.
  
      Parameters:
      ---------------------------------------------------------------------
      retval:   (modelId, errScore)