code: void init() {
          if (mEvaluator == null) {
              // We already handle int and float automatically, but not their Object
              // equivalents
              mEvaluator = (mValueType == Integer.class) ? sIntEvaluator :
                      (mValueType == Float.class) ? sFloatEvaluator :
                      null;
          }
          if (mEvaluator != null) {
              // KeyframeSet knows how to evaluate the common types - only give it a custom
              // evaluator if one has been set on this class
              mKeyframeSet.setEvaluator(mEvaluator);
          }
      }
docs: Internal function, called by ValueAnimator, to set up the TypeEvaluator that will be used
  to calculate animated values.