@Override
  public long getBytes(PropertyKey key) {
    checkArgument(key.getType() == PropertyKey.PropertyType.DATASIZE);
    return FormatUtils.parseSpaceSize((String) get(key));
  }
@Test
  public void getBytes() {
    mConfiguration.set(PropertyKey.USER_CLIENT_CACHE_PAGE_SIZE, "10b");
    assertEquals(10, mConfiguration.getBytes(PropertyKey.USER_CLIENT_CACHE_PAGE_SIZE));
  }