docs: public E popWithLimit(int minSize) {
          StackNode<E> oldTop, newTop;
  
          while (true) {
              oldTop = top.get();
              if (oldTop == null)
                  return null;
  
              if (oldTop.index + 1 <= minSize)
                  return null;
  
              newTop = oldTop.next;
              if (top.compareAndSet(oldTop, newTop))
                  break;
          }
  
          return oldTop.data;
      }