code: @Override
      public void stop(){
          if(isStarted){
              synchronized (this) {
                  if (isStarted) {
                      if (getLookupService() instanceof Closable) {
                          ((Closable) getLookupService()).stop();
                      }
                      isStarted = false;
                  }
              }
          }
      }
docs: Stop the LookupManagerImpl
  
  it is idempotent, it can be invoked multiple times while in same state and is not thread safe.