@Override
    public String toString() {
        return "ProcessorNode{" +
               "processorParameters=" + processorParameters +
               "} " + super.toString();
    }
Used to represent any type of stateless operation:

map, mapValues, flatMap, flatMapValues, filter, filterNot, branch
streams/src/main/java/org/apache/kafka/streams/kstream/internals/graph/ProcessorGraphNode.java