code: public void addMovingEndpoint(Token token, InetAddress endpoint)
      {
          assert endpoint != null;
  
          lock.writeLock().lock();
  
          try
          {
              movingEndpoints.add(Pair.create(token, endpoint));
          }
          finally
          {
              lock.writeLock().unlock();
          }
      }
docs: Add a new moving endpoint
  @param token token which is node moving to
  @param endpoint address of the moving node