@Override
        public String toString() {
            return "CapturedForward{" +
                "childName='" + childName + '\'' +
                ", timestamp=" + timestamp +
                ", keyValue=" + keyValue +
                '}';
        }
The data forwarded.

@return A key/value pair. Not null.
streams/test-utils/src/main/java/org/apache/kafka/streams/processor/MockProcessorContext.java