docs: private void renderAnimations() {
          Keyframe kf0, kf1, kf2, kf3;
          float midwayPoint = 0.2f;
          int duration = 500;
  
          // Set up animator for disappearing.
          kf0 = Keyframe.ofFloat(0f, 1);
          kf1 = Keyframe.ofFloat(midwayPoint, mTransitionMidRadiusMultiplier);
          kf2 = Keyframe.ofFloat(1f, mTransitionEndRadiusMultiplier);
          PropertyValuesHolder radiusDisappear = PropertyValuesHolder.ofKeyframe(
                  "animationRadiusMultiplier", kf0, kf1, kf2);
  
          kf0 = Keyframe.ofFloat(0f, 1f);
          kf1 = Keyframe.ofFloat(1f, 0f);
          PropertyValuesHolder fadeOut = PropertyValuesHolder.ofKeyframe("alpha", kf0, kf1);
  
          mDisappearAnimator = ObjectAnimator.ofPropertyValuesHolder(
                  this, radiusDisappear, fadeOut).setDuration(duration);
          mDisappearAnimator.addUpdateListener(mInvalidateUpdateListener);
  
  
          // Set up animator for reappearing.
          float delayMultiplier = 0.25f;
          float transitionDurationMultiplier = 1f;
          float totalDurationMultiplier = transitionDurationMultiplier + delayMultiplier;
          int totalDuration = (int) (duration * totalDurationMultiplier);
          float delayPoint = (delayMultiplier * duration) / totalDuration;
          midwayPoint = 1 - (midwayPoint * (1 - delayPoint));
  
          kf0 = Keyframe.ofFloat(0f, mTransitionEndRadiusMultiplier);
          kf1 = Keyframe.ofFloat(delayPoint, mTransitionEndRadiusMultiplier);
          kf2 = Keyframe.ofFloat(midwayPoint, mTransitionMidRadiusMultiplier);
          kf3 = Keyframe.ofFloat(1f, 1);
          PropertyValuesHolder radiusReappear = PropertyValuesHolder.ofKeyframe(
                  "animationRadiusMultiplier", kf0, kf1, kf2, kf3);
  
          kf0 = Keyframe.ofFloat(0f, 0f);
          kf1 = Keyframe.ofFloat(delayPoint, 0f);
          kf2 = Keyframe.ofFloat(1f, 1f);
          PropertyValuesHolder fadeIn = PropertyValuesHolder.ofKeyframe("alpha", kf0, kf1, kf2);
  
          mReappearAnimator = ObjectAnimator.ofPropertyValuesHolder(
                  this, radiusReappear, fadeIn).setDuration(totalDuration);
          mReappearAnimator.addUpdateListener(mInvalidateUpdateListener);
      }