### Question:
I18nProviderImpl extends AbstractGuavaCacheMBean<String,I18n> implements I18nProvider { @Override protected long getBytesLength(final I18n cacheObj) { return 0L; } I18nProviderImpl(); @Override String translate(final String key, final Resource resource); @Override String translate(final String key, final Locale locale); @Override String translate(final String key, final HttpServletRequest request); @Override I18n i18n(final Resource resource); @Override I18n i18n(final Locale locale); @Override I18n i18n(final HttpServletRequest request);  }### Answer:
@Test public void test_get_bytes_length() { assertEquals(0L, i18nProvider.getBytesLength(null)); }