class TopologyBuilder {

    public synchronized ProcessorTopology build(String applicationId, Integer topicGroupId) {
        Set<String> nodeGroup;
        if (topicGroupId != null) {
            nodeGroup = nodeGroups().get(topicGroupId);
        } else {
            // when nodeGroup is null, we build the full topology. this is used in some tests.
            nodeGroup = null;
        }
        return build(applicationId, nodeGroup);
    }

    public  TopologyBuilder();

}