$/**$ Given an add method:

$*$ Adds a new value to the end of the list.

$*$

$*$ @param value the integer value to be added to the list

$*/$

public void add$($int value$)\{$

if $($front $==$ null$)\{$

front $=$ new ListNode$($value$)$;

$\}$ else $\{$

ListNode current $=$ front;

while $($current$.$next $!=$ null$)\{$

current $=$ current.next;

$\}$

current.next $=$ new ListNode$($value$)$;

$\}$

$\}$

Write a function: public void stutter$()$ This method will double the size of the list by replacing every integer in the list with two of that integer. If the list is empty, simply return. For example, suppose a variable list stores the values $[1,8,19,4,17].$ After a call of list.stutter$(),$ it should store $[1,1,8,8,19,19,4,4,17,17].$