Write some code that will use an iterator to duplicate every item in an instance of String...

Write some code that will use an iterator to duplicate every item in an instance of StringLinkedListWithIterator For example, if the list contains "a", "b", and "c", after the code runs, it will contain "a", "a", "b", "b", "c", and "c".

 /**Linked list with an iterator. One node is the "current node." Initially, the current node is the first node. It can be changed to the next node until the iteration has moved beyond the end of the list.*/public class StringLinkedListWithIterator{   private ListNode head;   private ListNode current;   private ListNode previous;   public StringLinkedListWithIterator()   {      head = null;      current = null;      previous = null;   }   public void addANodeToStart(String addData)   {      head = new ListNode(addData, head);      if ((current == head.link) && (current != null))	 //if current is at old start node	 previous = head;   }/**Sets iterator to beginning of list.*/public void resetIteration(){   current = head;   previous = null;}/**Returns true if iteration is not finished.*/public boolean moreToIterate(){   return current != null;}/**Advances iterator to next node.*/public void goToNext(){   if (current != null)   {      previous = current;      current = current.link;   }   else if (head != null)   {      System.out.println("Iterated too many times or uninitialized iteration.");      System.exit(0);   }   else   {      System.out.println("Iterating with an empty list.");      System.exit(0);   }}/**Returns the data at the current node.*/public String getDataAtCurrent(){   String result = null;   if (current != null)	 result = current.data;      else      {	 System.out.println(		  "Getting data when current is not at any node.");	 System.exit(0);      }      return result;   }/**Replaces the data at the current node./*public void setDataAtCurrent(String newData){   if (current != null)   {      current.data = newData;   }   else   {      System.out.println(	       "Setting data when current is not at any node.");      System.exit(0);   }}/**Inserts a new node containing newData after the current node. The current node is the same after invocation as it is before. Precondition: List is not empty; current node is not beyond the entire list.*/public void insertNodeAfterCurrent(String newData){   ListNode newNode = new LisNode();   newNode.data = newData;   if (current != null)   {      newNode.link = current.link;      current.link = newNode;   }    else if (head != null)   {      System.out.println(	       "Inserting when iterator is past all " +	       "nodes or is not initialized.");      System.exit(0);   }else{   System.out.println(	    "Using insertNodeAfterCurrent with empty list.";    System.exit(0);    }}/**Deletes the current node. After the invocation, the current node is either the node after the deleted node or null if there is no next node.*/public void deleteCurrentNode(){   if ((current != null) && (previous == null))   {      previous.link = current.link;      current = current.link;   }   else if ((current != null) && (previous == null))   {//At head node      head = current.link;      current = head;   }   else //current==null    {      System.out.println(	 "Deleting with uninitialized current or an empty " +	 "list.");      System.exit(0);   } }   The methods length, onList, find, and showList, as well as the private inner class ListNode are the same as in   private class ListNode      {	 private String data;	 private ListNode link;	 public ListNode()      {	 link = null;	 data = null;      }	 public ListNode(String newData, ListNode linkValue)   {	 data = newData;	 link = linkValue;   }      }The method toArray is the same as /**Returns an array of the elements on the list.*/public String[] toArray()   {      String[] anArray = new String[length()];      ListNode position = head;      int i = 0;      while (position != null)   {	anArray[i] = position.data;	 i++;	 position = position.link;   }	 return anArray;      }   }