code: @Override
      public List<Pair<Long, String>> getLastNCanceledInstances() {
          List<Pair<Long, String>> list = new ArrayList<Pair<Long, String>>();
          synchronized (recentCanceledQueue) {
              for (Pair<Long, String> aRecentCanceledQueue : recentCanceledQueue) {
                  list.add(aRecentCanceledQueue);
              }
          }
          Collections.reverse(list);
          return list;
      }
docs: Get the N instances that have most recently canceled.
  
  @return