code: def __deleteModelCheckpoint(self, modelID):
      
  
      checkpointID = \
          self._jobsDAO.modelsGetFields(modelID, ['modelCheckpointId'])[0]
  
      if checkpointID is None:
        return
  
      try:
        shutil.rmtree(os.path.join(self._experimentDir, str(self._modelCheckpointGUID)))
      except:
        self._logger.warn("Failed to delete model checkpoint %s. "\
                          "Assuming that another worker has already deleted it",
                          checkpointID)
        return
  
      self._jobsDAO.modelSetFields(modelID,
                                   {'modelCheckpointId':None},
                                   ignoreUnchanged=True)
      return
docs: Delete the stored checkpoint for the specified modelID. This function is
      called if the current model is now the best model, making the old model's
      checkpoint obsolete
  
      Parameters:
      -----------------------------------------------------------------------
      modelID:      The modelID for the checkpoint to delete. This is NOT the
                    unique checkpointID