### Question:
LinkedStack implements Stack<E> { @Override public int size() { return 0; }  static void main(String[] args); @Override int size(); @Override boolean isEmpty(); @Override void push(E e); @Override E top(); @Override E pop();  }### Answer:
@Test void testSize() { LinkedStack<Integer> s = new LinkedStack<>(); for(int i = 0; i < 10; ++i) s.push(i); assertEquals(10, s.size()); }