@Override
    public boolean isOpen() {
        return store.isOpen();
    }
@Test
    public void shouldReturnIsOpenForVersionedStore() {
        givenWrapperWithVersionedStore();

        // test "isOpen = true"
        when(versionedStore.isOpen()).thenReturn(true);
        assertThat(wrapper.isOpen(), equalTo(true));

        // test "isOpen = false"
        when(versionedStore.isOpen()).thenReturn(false);
        assertThat(wrapper.isOpen(), equalTo(false));
    }