protected long doRefresh(boolean asynchronous, @Nullable Runnable postAction) {
    if (!asynchronous) {
      ApplicationManager.getApplication().assertWriteIntentLockAcquired();
    }

    for (VirtualFileSystem fileSystem : getPhysicalFileSystems()) {
      if (!(fileSystem instanceof CachingVirtualFileSystem)) {
        fileSystem.refresh(asynchronous);
      }
    }

    return 0;
  }
protected long doRefresh(boolean asynchronous, @Nullable Runnable postAction)