// Adds element to this collection.
// Precondition: element is not already in the collection
public void add(T element) {
if (node == null) {
node = new LLNode<T>(element);
size++;
} else {
LLNode<T> temp = node;
while (temp.getLink() != null) {
temp = temp.getLink();
}
temp.setLink(new LLNode<T>(element));
size++;
}
}
