private String nodesAsString() {
            final StringBuilder sb = new StringBuilder();
            for (final TopologyDescription.Node node : nodes) {
                sb.append("    ");
                sb.append(node);
                sb.append('\n');
            }
            return sb.toString();
        }
@return names of all source topics, including the application id/named topology prefix for repartition sources
streams/src/main/java/org/apache/kafka/streams/processor/internals/InternalTopologyBuilder.java