@Override
  @GuardedBy("getLock()")
  public PageInfo getPageInfo(PageId pageId) throws PageNotFoundException {
    if (!mPages.contains(INDEX_PAGE_ID, pageId)) {
      throw new PageNotFoundException(String.format("Page %s could not be found", pageId));
    }
    PageInfo pageInfo = mPages.getFirstByField(INDEX_PAGE_ID, pageId);
    pageInfo.getLocalCacheDir().getEvictor().updateOnGet(pageId);
    return pageInfo;
  }
@Test
  public void getPageInfoNotExist() throws Exception {
    assertThrows(PageNotFoundException.class, () -> mMetaStore.getPageInfo(mPage));
  }