code: func CloseTracer(tracer opentracing.Tracer) error {
  	switch lsTracer := tracer.(type) {
  	case Tracer:
  		lsTracer.Close(context.Background())
  		return nil
  	case *tracerv0_14:
  		return CloseTracer(lsTracer.Tracer)
  	default:
  		return newEventUnsupportedTracer(tracer)
  	}
  }
docs: // CloseTracer closes the tracer
  // DEPRECATED: use Close instead.