code: func (t *TrivialRecorder) RecordSpan(span basictracer.RawSpan) {
  	fmt.Printf(
  		"RecordSpan: %v[%v, %v us] --> %v logs. context: %v; baggage: %v\n",
  		span.Operation, span.Start, span.Duration, len(span.Logs),
  		span.Context, span.Context.Baggage)
  	for i, l := range span.Logs {
  		fmt.Printf(
  			"    log %v @ %v: %v\n", i, l.Timestamp, l.Fields)
  	}
  }
docs: // RecordSpan complies with the basictracer.Recorder interface.