@Test
    void all_clusters_bucket_spaces_config_contains_mappings_across_all_clusters() {
        VespaModel model = createDualContentCluster();
        AllClustersBucketSpacesConfig.Builder builder = new AllClustersBucketSpacesConfig.Builder();
        model.getConfig(builder, "client");
        AllClustersBucketSpacesConfig config = builder.build();

        assertEquals(2, config.cluster().size());

        assertClusterHasBucketSpaceMappings(config, "foo_c", List.of("bunnies", "hares"), List.of());
        assertClusterHasBucketSpaceMappings(config, "bar_c", List.of(), List.of("rabbits"));
    }
Here there is no good choice.
config-model/src/test/java/com/yahoo/vespa/model/content/ContentClusterTest.java