@Override
  public boolean delete(PageId pageId) {
    // since bloom filter does not support deleting, always return false here
    return false;
  }
@Test
  public void delete() throws Exception {
    assertTrue(mCacheManager.put(PAGE_ID1, PAGE1_BYTES, SCOPE1));
    assertEquals(PAGE1_BYTES, mCacheManager.get(PAGE_ID1, PAGE1_BYTES, SCOPE1));
    assertFalse(mCacheManager.delete(PAGE_ID1));
    assertEquals(PAGE1_BYTES, mCacheManager.get(PAGE_ID1, PAGE1_BYTES, SCOPE1));
    mCacheManager.updateWorkingSetSize();
    // bloom filter does not support deleting, so PAGE_ID1 is not deleted actually
    assertEquals(1, mCacheManager.getShadowCachePages());
    assertEquals(mCacheManager.getShadowCacheBytes(), PAGE1_BYTES);
  }