@Override
  public boolean isUpToDate(@NotNull Url url, @NotNull VirtualFile local) {
    long now = System.currentTimeMillis();
    // don't update more frequently than once in 4 hours
    if (now - myLastUpdateTime < UPDATE_DELAY) {
      return true;
    }

    myLastUpdateTime = now;
    String path = local.getPath();

    if (now - new File(path).lastModified() < UPDATE_DELAY) {
      return true;
    }

    if (checkUpToDate(url, path, ETAG_HEADER)) return true;
    if (checkUpToDate(url, path, LAST_MODIFIED_HEADER)) return true;

    return false;
  }
@Override
  public boolean isUpToDate(@NotNull Url url, @NotNull VirtualFile local)