def insert(self, value, index):
insert_node = ListNode(value)
current_index = 0
current_node = self.head
while (current_index < index - 1):
current_index += 1
current_node = current_node.next_node
print current_node.value
insert_node.next_node = current_node.next_node
current_node.next_node = insert_node
def prepend(self, value):
new_node = ListNode(value)
new_node.next_node = self.head
self.head = new_node
