I started this, please help

In JAVA : Implement an algorithm for concatenating two singly linked lists L and M, into a single list L that contains all the nodes of L followed by all the nodes of M. Write the code and test it.

Modify the SinglyLinkedList class to contain the method: public void concatenate(SinglyLinkedList other) { ... }

public static void main(String[] args) { SinglyLinkedList listL = new SinglyLinkedList<>(); SinglyLinkedList listM = new SinglyLinkedList<>(); listL.addFirst(26); listL.addFirst(13); listL.addFirst(72); listL.addFirst(91); System.out.println(listL);