public Optional<Service> getService(String configId) {
        return getConfigProducer(configId)
                .filter(Service.class::isInstance)
                .map(Service.class::cast);
    }
Returns the Service with the given id if such configId exists and it belongs to a Service ConfigProducer.

@param  configId The configId, e.g. "search.0/tld.0"
@return Service with the given configId
config-model/src/main/java/com/yahoo/config/model/producer/AbstractConfigProducerRoot.java