String getConfigIdPrefix() {
        if (this instanceof AbstractConfigProducerRoot || this instanceof ApplicationConfigProducerRoot) {
            return "";
        }
        if (currentConfigId() == null) {
            return null;
        }
        return getConfigId() + "/";
    }
Returns a list of all the children of this who are instances of Service
config-model/src/main/java/com/yahoo/config/model/producer/TreeConfigProducer.java