code: func NewTracing(serviceName string, spanNameLimit int, trackingBackend TrackingBackend) (*Tracing, error) {
  	tracing := &Tracing{
  		ServiceName:   serviceName,
  		SpanNameLimit: spanNameLimit,
  	}
  
  	var err error
  	tracing.tracer, tracing.closer, err = trackingBackend.Setup(serviceName)
  	if err != nil {
  		return nil, err
  	}
  	return tracing, nil
  }
docs: // NewTracing Creates a Tracing.