### Question:
linkedList { public linkedList() { start = null; end = null; size = 0; } linkedList(); boolean isEmpty(); int getSize(); void insertAtStart(int val); void insertAtEnd(int val); void insertAtPos(int val , int pos); void deleteAtPos(int pos); void display(); public int size; }### Answer:
@Test public void testLinkedList(){ LinkedList<Integer> intList = new LinkedList<Integer>(); assertTrue(intList.add(1)); assertTrue(intList.add(2)); assertEquals(new Integer(1), intList.head()); assertEquals(new Integer(2), intList.tail()); assertTrue(intList.add(3)); assertEquals(new Integer(3), intList.tail()); assertEquals(3, intList.size()); assertFalse(intList.add(null)); assertTrue(intList.remove(new Integer(3))); assertFalse(intList.contains(new Integer(3))); assertEquals(2, intList.size()); assertTrue(intList.contains(new Integer(2))); assertFalse(intList.remove(new Integer(3))); }