public String toString(final String indent) {
        final StringBuilder sb = new StringBuilder(indent + name + ":\n");
        if (stateStores != null && !stateStores.isEmpty()) {
            sb.append(indent).append("\tstates:\t\t[");
            for (final String store : stateStores) {
                sb.append(store);
                sb.append(", ");
            }
            sb.setLength(sb.length() - 2);  // remove the last comma
            sb.append("]\n");
        }
        return sb.toString();
    }
@return a string representation of this node starting with the given indent, useful for debugging.
streams/src/main/java/org/apache/kafka/streams/processor/internals/ProcessorNode.java