code: private void animateExpand() {
          mCloseBtn.setVisibility(View.VISIBLE);
          mMidContainer.setVisibility(View.VISIBLE);
          mRightContainer.setVisibility(View.VISIBLE);
          mLeftContainer.setVisibility(View.VISIBLE);
  
          setButtonsVisibleForPreHC();
  
          ANIMATION_COUNTER = 0;
  
          ViewPropertyAnimator.animate(mMidContainer).setDuration(ANIMATION_DURATION).translationYBy(-TRANSLATION_Y).setInterpolator(overshoot).setListener(ON_EXPAND_COLLAPSE_LISTENER);
          ViewPropertyAnimator.animate(mRightContainer).setDuration(ANIMATION_DURATION).translationYBy(-TRANSLATION_Y).translationXBy(TRANSLATION_X).setInterpolator(overshoot).setListener(ON_EXPAND_COLLAPSE_LISTENER);
          ViewPropertyAnimator.animate(mLeftContainer).setDuration(ANIMATION_DURATION).translationYBy(-TRANSLATION_Y).translationXBy(-TRANSLATION_X).setInterpolator(overshoot).setListener(ON_EXPAND_COLLAPSE_LISTENER);
      }
docs: Start expand animation