code: func (as *Step) LogLine(label, line string) bool {
  	updated := false
  
  	name, ok := as.logLines[label]
  	if !ok {
  		// No entry for this log line. Create a new one and register it.
  		//
  		// This will appear as:
  		// [BASE]/logs/[label]/[ord]
  		subName, err := types.MakeStreamName("s_", "logs", label, strconv.Itoa(as.logLineCount[label]))
  		if err != nil {
  			panic(fmt.Errorf("failed to generate log stream name for [%s]: %s", label, err))
  		}
  		name = as.BaseStream(subName)
  		as.AddLogdogStreamLink("", label, "", name)
  
  		as.logLines[label] = name
  		as.logLineCount[label]++
  		updated = true
  	}
  
  	as.s.Callbacks.StepLogLine(as, name, label, line)
  	return updated
  }
docs: // LogLine emits a log line for a specified log label.