code: public void insertAfter(Token before, TokenList list ) {
          Token after = before.next;
  
          before.next = list.first;
          list.first.previous = before;
          if( after == null ) {
              last = list.last;
          } else {
              after.previous = list.last;
              list.last.next = after;
          }
          size += list.size;
      }
docs: Inserts the LokenList immediately following the 'before' token