@Override
    public String toString() {
        return "ProcessorRecordContext{" +
            "topic='" + topic + '\'' +
            ", partition=" + partition +
            ", offset=" + offset +
            ", timestamp=" + timestamp +
            ", headers=" + headers +
            '}';
    }
Equality is implemented in support of tests, *not* for use in Hash collections, since this class is mutable
due to the {@link Headers} field it contains.
streams/src/main/java/org/apache/kafka/streams/processor/internals/ProcessorRecordContext.java