@Override
  public boolean delete(PageId pageId) {
    return mCacheManager.delete(pageId);
  }
@Test
  public void delete() throws Exception {
    assertTrue(mCacheManager.put(PAGE_ID1, PAGE1));
    assertEquals(PAGE1.length, mCacheManager.get(PAGE_ID1, PAGE1.length, mBuf, 0));
    assertArrayEquals(PAGE1, mBuf);
    assertTrue(mCacheManager.delete(PAGE_ID1));
    assertEquals(0, mCacheManager.get(PAGE_ID1, PAGE1.length, mBuf, 0));
    mCacheManager.updateWorkingSetSize();
    mCacheManager.updateWorkingSetSize();
    mCacheManager.updateWorkingSetSize();
    assertEquals(1, mCacheManager.getShadowCachePages());
    assertEquals(mCacheManager.getShadowCacheBytes(), PAGE1.length);
  }