Problem
Add a method swapTwoNodes to DoublyLinkedList class from week 2 lecture examples. This method should swap two nodes node1 and node2 (and not just their contents) given references only to node1 and node2. The new method should check if node1 and node2 are the same node, etc. Write the main method to test the swapTwoNodes method. Hint: You may need to traverse the list.