private static String topicsToString(final String indent, final List<String> topics) {
        final StringBuilder sb = new StringBuilder();
        sb.append(indent).append("\ttopics:\t\t[");
        for (final String topic : topics) {
            sb.append(topic);
            sb.append(", ");
        }
        sb.setLength(sb.length() - 2);  // remove the last comma
        sb.append("]\n");
        return sb.toString();
    }
Produces a string representation containing useful information this topology.
This is useful in debugging scenarios.
@return A string representation of this instance.
streams/src/main/java/org/apache/kafka/streams/processor/internals/ProcessorTopology.java