public static void main(String args[]){
        LinkList ll = new LinkList();
        Node head = null;
        head = ll.addNode(11, head);
        head = ll.addNode(12, head);
        head = ll.addNode(-3, head);
        head = ll.addNode(45, head);
        head = ll.addNode(5, head);
        head = ll.addNode(101, head);
    
        InsertionSortLinkList isll = new InsertionSortLinkList();
        head = isll.sort(head);
        ll.printList(head);
    }
http://www.geeksforgeeks.org/given-a-linked-list-which-is-sorted-how-will-you-insert-in-sorted-way/
Test cases:
0 nodes
1 nodes 
2 or more nodes
already sorted
reverse sorted
negative positive numbers
src/com/interview/linklist/InsertionSortLinkList.java