code: func (e *LoadStatsExec) Next(ctx context.Context, req *chunk.RecordBatch) error {
  	req.GrowAndReset(e.maxChunkSize)
  	if len(e.info.Path) == 0 {
  		return errors.New("Load Stats: file path is empty")
  	}
  	val := e.ctx.Value(LoadStatsVarKey)
  	if val != nil {
  		e.ctx.SetValue(LoadStatsVarKey, nil)
  		return errors.New("Load Stats: previous load stats option isn't closed normally")
  	}
  	e.ctx.SetValue(LoadStatsVarKey, e.info)
  	return nil
  }
docs: // Next implements the Executor Next interface.