code: func (l *Log) fetch(nextToken *string, start int64, ch chan<- *Event) (*string, int64, error) {
  	res, err := l.Service.FilterLogEvents(&cloudwatchlogs.FilterLogEventsInput{
  		LogGroupName:  &l.GroupName,
  		FilterPattern: &l.FilterPattern,
  		StartTime:     &start,
  		NextToken:     nextToken,
  	})
  
  	if e, ok := err.(awserr.Error); ok {
  		if e.Code() == "ResourceNotFoundException" {
  			l.Log.Debug("not found")
  			return nil, 0, nil
  		}
  	}
  
  	if err != nil {
  		return nil, 0, err
  	}
  
  	for _, event := range res.Events {
  		start = *event.Timestamp + 1
  		ch <- &Event{
  			GroupName: l.GroupName,
  			Message:   *event.Message,
  		}
  	}
  
  	return res.NextToken, start, nil
  }
docs: // fetch logs relative to the given token and start time. We ignore when the log group is not found.