code: func (e *LoadDataExec) Next(ctx context.Context, req *chunk.RecordBatch) error {
  	req.GrowAndReset(e.maxChunkSize)
  	// TODO: support load data without local field.
  	if !e.IsLocal {
  		return errors.New("Load Data: don't support load data without local field")
  	}
  	// TODO: support lines terminated is "".
  	if len(e.loadDataInfo.LinesInfo.Terminated) == 0 {
  		return errors.New("Load Data: don't support load data terminated is nil")
  	}
  
  	sctx := e.loadDataInfo.ctx
  	val := sctx.Value(LoadDataVarKey)
  	if val != nil {
  		sctx.SetValue(LoadDataVarKey, nil)
  		return errors.New("Load Data: previous load data option isn't closed normal")
  	}
  	if e.loadDataInfo.Path == "" {
  		return errors.New("Load Data: infile path is empty")
  	}
  	sctx.SetValue(LoadDataVarKey, e.loadDataInfo)
  
  	return nil
  }
docs: // Next implements the Executor Next interface.