docs: public float fractionTraveled() {
      float fractionTraveled = 1;
  
      if (routeLeg().distance() > 0) {
        fractionTraveled = (float) (distanceTraveled() / routeLeg().distance());
        if (fractionTraveled < 0) {
          fractionTraveled = 0;
        }
      }
      return fractionTraveled;
    }