Program: 86234
Project: 86234
Buggy source:
private void collapse(final CompleteListener listener){
  AnimatorSet set=new AnimatorSet();
  View expandedView=expandedCard.getChildAt(0);
  int defaultMargin=context.getResources().getDimensionPixelSize(R.dimen.card_side_margin_default);
  int expandedMargin=context.getResources().getDimensionPixelSize(R.dimen.card_side_margin_selected);
  int marginDifference=expandedMargin - defaultMargin;
  List<Animator> animators=new ArrayList<>();
  addAll(animators,ObjectAnimator.ofFloat(lowerCard,"String_Node_Str",0,lowerTranslationY),ObjectAnimator.ofFloat(expandedCard,"String_Node_Str",0,expandedTranslationY),ObjectAnimator.ofFloat(expandedCard,"String_Node_Str",context.getResources().getDimension(R.dimen.card_elevation_selected),context.getResources().getDimension(R.dimen.card_elevation_default)),ObjectAnimator.ofInt(expandedCard,"String_Node_Str",expandedCard.getBottom(),expandedCard.getBottom() + unexpandedHeight - expandedView.getHeight()),ObjectAnimator.ofInt(expandedCard,"String_Node_Str",expandedCard.getLeft(),expandedCard.getLeft() - marginDifference),ObjectAnimator.ofInt(expandedCard,"String_Node_Str",expandedCard.getRight(),expandedCard.getRight() + marginDifference));
  if (interceptor != null)   animators.addAll(interceptor.getCollapseAnimations(-heightDifference,expandedView));
  set.playTogether(animators);
  set.addListener(new AnimatorListenerAdapter(){
    @Override public void onAnimationEnd(    Animator animation){
      super.onAnimationEnd(animation);
      if (interceptor != null)       interceptor.onCollapseAnimationEnd();
      mainCard.setVisibility(View.VISIBLE);
      upperCard.setVisibility(View.GONE);
      lowerCard.setVisibility(View.GONE);
      expandedCard.clearAnimation();
      expandedCard.setVisibility(View.GONE);
      llUpper.removeAllViews();
      llLower.removeAllViews();
      expandedCard.removeAllViews();
      expandedPosition=-1;
      unexpandedHeight=0;
      expandedTranslationY=0;
      lowerTranslationY=0;
      heightDifference=0;
      if (listener != null)       listener.onComplete();
    }
  }
);
  set.setDuration(ANIMATION_DURATION).start();
}

Fixed version (ground truth):
private void collapse(final CompleteListener listener){
  AnimatorSet set=new AnimatorSet();
  View expandedView=expandedCard.getChildAt(0);
  if (expandedView == null) {
    return;
  }
  int defaultMargin=context.getResources().getDimensionPixelSize(R.dimen.card_side_margin_default);
  int expandedMargin=context.getResources().getDimensionPixelSize(R.dimen.card_side_margin_selected);
  int marginDifference=expandedMargin - defaultMargin;
  List<Animator> animators=new ArrayList<>();
  addAll(animators,ObjectAnimator.ofFloat(lowerCard,"String_Node_Str",0,lowerTranslationY),ObjectAnimator.ofFloat(expandedCard,"String_Node_Str",0,expandedTranslationY),ObjectAnimator.ofFloat(expandedCard,"String_Node_Str",context.getResources().getDimension(R.dimen.card_elevation_selected),context.getResources().getDimension(R.dimen.card_elevation_default)),ObjectAnimator.ofInt(expandedCard,"String_Node_Str",expandedCard.getBottom(),expandedCard.getBottom() + unexpandedHeight - expandedView.getHeight()),ObjectAnimator.ofInt(expandedCard,"String_Node_Str",expandedCard.getLeft(),expandedCard.getLeft() - marginDifference),ObjectAnimator.ofInt(expandedCard,"String_Node_Str",expandedCard.getRight(),expandedCard.getRight() + marginDifference));
  if (interceptor != null)   animators.addAll(interceptor.getCollapseAnimations(-heightDifference,expandedView));
  set.playTogether(animators);
  set.addListener(new AnimatorListenerAdapter(){
    @Override public void onAnimationEnd(    Animator animation){
      super.onAnimationEnd(animation);
      resetViews();
      if (listener != null)       listener.onComplete();
    }
  }
);
  set.setDuration(ANIMATION_DURATION).start();
}