private Mono<ServerResponse> fetchThemeConfig(ServerRequest request) {
        return themeNameInPathVariableOrActivated(request)
            .flatMap(themeName -> client.fetch(Theme.class, themeName))
            .mapNotNull(theme -> theme.getSpec().getConfigMapName())
            .flatMap(configMapName -> client.fetch(ConfigMap.class, configMapName))
            .flatMap(configMap -> ServerResponse.ok().bodyValue(configMap));
    }
@Test
    void fetchThemeConfig() {
        Theme theme = new Theme();
        theme.setMetadata(new Metadata());
        theme.getMetadata().setName("fake");
        theme.setSpec(new Theme.ThemeSpec());
        theme.getSpec().setConfigMapName("fake-config");

        when(client.fetch(eq(ConfigMap.class), eq("fake-config")))
            .thenReturn(Mono.just(new ConfigMap()));

        when(client.fetch(eq(Theme.class), eq("fake"))).thenReturn(Mono.just(theme));
        webTestClient.get()
            .uri("/themes/fake/config")
            .exchange()
            .expectStatus().isOk();

        verify(client).fetch(eq(ConfigMap.class), eq("fake-config"));
        verify(client).fetch(eq(Theme.class), eq("fake"));
    }