code: @Override
      public void setInterpolator(/*Time*/Interpolator value) {
          if (value != null) {
              mInterpolator = value;
          } else {
              mInterpolator = new LinearInterpolator();
          }
      }
docs: The time interpolator used in calculating the elapsed fraction of this animation. The
  interpolator determines whether the animation runs with linear or non-linear motion,
  such as acceleration and deceleration. The default value is
  {@link android.view.animation.AccelerateDecelerateInterpolator}
  
  @param value the interpolator to be used by this animation. A value of <code>null</code>
  will result in linear interpolation.