code: public void updateExtensions()
      {
          // Start a background thread to get more details about the found extensions
          Thread thread = new Thread(new Runnable()
          {
              @Override
              public void run()
              {
                  DefaultCoreExtensionRepository.this.scanner
                      .updateExtensions(DefaultCoreExtensionRepository.this.extensions.values());
              }
          });
  
          thread.setPriority(Thread.MIN_PRIORITY);
          thread.setDaemon(true);
          thread.setName("Core extension repository updater");
          thread.start();
      }
docs: Update core extensions only if there is any remote repository and it's not disabled.