code: func GetLightStepAccessToken(tracer opentracing.Tracer) (string, error) {
  	switch lsTracer := tracer.(type) {
  	case Tracer:
  		return lsTracer.Options().AccessToken, nil
  	case *tracerv0_14:
  		return GetLightStepAccessToken(lsTracer.Tracer)
  	default:
  		return "", newEventUnsupportedTracer(tracer)
  	}
  }
docs: // GetLightStepAccessToken returns the currently configured AccessToken.