code: protected float getInterpolatedCurrentKeyframeProgress() {
      Keyframe<K> keyframe = getCurrentKeyframe();
      if (keyframe.isStatic()) {
        return 0f;
      }
      //noinspection ConstantConditions
      return keyframe.interpolator.getInterpolation(getLinearCurrentKeyframeProgress());
    }
docs: Takes the value of {@link #getLinearCurrentKeyframeProgress()} and interpolates it with
  the current keyframe's interpolator.