You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: slow_query_test.go
    path of file: ./repos/tidb/pkg/executor
    
    the code of the file until where you have to start completion: // Copyright 2019 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not us
    
func parseLog(retriever *slowQueryRetriever, sctx sessionctx.Context, reader *bufio.Reader) ([][]types.Datum, error) {
	retriever.taskList = make(chan slowLogTask, 100)
	ctx := context.Background()
	retriever.parseSlowLog(ctx, sctx, reader, 64)
	task, ok := <-retriever.taskList
	if !ok {
		return nil, nil
	}
	var rows [][]types.Datum
	var err error
	result := <-task.resultCh
	rows, err = result.rows, result.err
	return rows, err
}