docs: @Override
      public LookupManager getLookupManager(){
          if(lookupManager == null){
              synchronized(this){
                  if(lookupManager == null){
                      LookupManagerImpl lookup = new LookupManagerImpl(getDirectoryServiceClientManager());
                      lookup.start();
                      lookupManager = lookup;
                  }
              }
          }
          return lookupManager;
      }