@Override
    public long approximateNumEntries() {
        return inner.approximateNumEntries();
    }
@Test
    public void shouldForwardApproximateNumEntries() {
        when(mockedKeyValueTimestampStore.approximateNumEntries()).thenReturn(42L);

        assertThat(readOnlyKeyValueStoreFacade.approximateNumEntries(), is(42L));
    }