code: func (m *Meta) GetAllDDLJobsInQueue(jobListKeys ...JobListKeyType) ([]*model.Job, error) {
  	listKey := m.jobListKey
  	if len(jobListKeys) != 0 {
  		listKey = jobListKeys[0]
  	}
  
  	values, err := m.txn.LGetAll(listKey)
  	if err != nil || values == nil {
  		return nil, errors.Trace(err)
  	}
  
  	jobs := make([]*model.Job, 0, len(values))
  	for _, val := range values {
  		job := &model.Job{}
  		err = job.Decode(val)
  		if err != nil {
  			return nil, errors.Trace(err)
  		}
  		jobs = append(jobs, job)
  	}
  
  	return jobs, nil
  }
docs: // GetAllDDLJobsInQueue gets all DDL Jobs in the current queue.
  // The length of jobListKeys can only be 1 or 0.
  // If its length is 1, we need to replace m.jobListKey with jobListKeys[0].
  // Otherwise, we use m.jobListKey directly.