private String servicesWithGroups(int groupCount, double minGroupUpRatio) {
        String services = String.format("<?xml version='1.0' encoding='UTF-8' ?>" +
                "<services version='1.0'>" +
                "  <container id='default' version='1.0' />" +
                "  <content id='storage' version='1.0'>" +
                "    <redundancy>%d</redundancy>" +
                "    <documents>" +
                "      <document mode='index' type='type1' />" +
                "    </documents>" +
                "  <group name='root'>", groupCount);
        String distribution = switch (groupCount) {
            case 1, 2 -> "    <distribution partitions='1|*'/>";
            case 3 -> "    <distribution partitions='1|1|*'/>";
            case 4 -> "    <distribution partitions='1|1|1|*'/>";
            case 5 -> "    <distribution partitions='1|1|1|1|*'/>";
            case 6 -> "    <distribution partitions='1|1|1|1|1|*'/>";
            default -> throw new IllegalArgumentException("Does not support groupCount > 6");
        };
        services += distribution;
        for (int i = 0; i < groupCount; i++) {
            services += String.format("    <group name='g-%d' distribution-key='%d'>" +
                                              "      <node hostalias='mockhost' distribution-key='%d'/>" +
                                              "    </group>",
                                      i, i, i);
        }
        return services +
                String.format(Locale.US, "  </group>" +
                "    <tuning>" +
                "      <cluster-controller>" +
                "        <groups-allowed-down-ratio>%f</groups-allowed-down-ratio>" +
                "      </cluster-controller>" +
                "    </tuning>" +
                "    <engine>" +
                "      <proton>" +
                "        <searchable-copies>%d</searchable-copies>" +
                "      </proton>" +
                "    </engine>" +
                "  </content>" +
                " </services>", minGroupUpRatio, groupCount);
    }
Here there is no good choice.
config-model/src/test/java/com/yahoo/vespa/model/content/ContentClusterTest.java