code: public void playTogether(Collection<Animator> items) {
          if (items != null && items.size() > 0) {
              mNeedsSort = true;
              Builder builder = null;
              for (Animator anim : items) {
                  if (builder == null) {
                      builder = play(anim);
                  } else {
                      builder.with(anim);
                  }
              }
          }
      }
docs: Sets up this AnimatorSet to play all of the supplied animations at the same time.
  
  @param items The animations that will be started simultaneously.