@ApiStatus.Internal
  public boolean cleanupExtensionCache() {
    synchronized (myExtensions) {
      JpsPluginManager manager = myPluginManager;
      if (manager != null) {
        int stamp = manager.getModificationStamp();
        if (myModificationStamp.getAndSet(stamp) != stamp) {
          myExtensions.clear();
          return true;
        }
      }
      return false;
    }
  }
@ApiStatus.Internal
  public boolean cleanupExtensionCache()