listing linked lists continued /public link(long dd/constructor ddata dd/public void displaylink(/display ourself system out print(ddata ")/end class link ///////////////////////////////////////////////////////////////class linklist private link first/ref to first item on list /public linklist(/constructor first null/no items on list yet /public boolean isempty(/true if list is empty return (first==null)/public void insertfirst(long dd/insert at start of list /make new link link newlink new link(dd)newlink next first/newlink --old first first newlink/first --newlink /public long deletefirst(/delete first item /(assumes list not emptylink temp first/save reference to link first first next/delete itfirst-->old next return temp ddata/return deleted link /public void displaylist(link current first/start at beginning of list while(current !null/until end of listcurrent displaylink()/print data current current next/move to next link system out println("")