Java Practice-It || 16.5 countDuplicates (pt.1) || implementing, ListNodes, LinkedLists

Question:

[1, 1, 1, 3, 3, 6, 9, 15, 15, 23, 23, 23, 40, 40]
Remember that you may assume that the list is in sorted order, so any duplicates would occur consecutively.

Assume that you are adding this method to the LinkedIntList class as defined below:

public class LinkedIntList {
private ListNode front; // null for an empty list
...
}