Lab Exercise 1: The following program implements LinkedList. Write the code to implement addFirst(), addLast(), Exercisel Task: 1- addFirst () method so that it add a first node to the current list. 2- addlast () method so that it add a node at the end of the current list. 3- removeFirst () method so that it remove the first node of the current list 4- remove (index) method to remove the node from the index position 5- Identify the time complexity of the remove (index) method (big O)