Consider the following code which implements the add method in the DList class from the course videos:

public void add(int pIndex, Integer pData) throws IndexOutOfBoundsException {

if (pIndex < 0 || pIndex > getSize())

throw new IndexOutOfBoundsException();

if (pIndex == getSize()) { //adding node to the end of the list

Node newNode = new Node(pData, getTail(), null);

if (isEmpty())

setHead(newNode); //////////LINE 1

else

getTail().setNext(newNode); //////////LINE 2

setTail(newNode);

}

else {

Node node = getNodeAt(pIndex);

Node newNode = new Node(pData, node.getPrev(), node);

if (pIndex != 0)

node.getPrev().setNext(newNode);

node.setPrev(newNode);

if (pIndex == 0)

setHead(newNode);

}

setSize(getSize() + 1);

}

Explain what will happen if the lines indicated are swapped.