TraceKafkaConsume extracts the pathway from to the kafka message header to the context.

TraceKafkaProduce appends the pathway in the context to the kafka message header.

PartitionAny is used to represent that partition is not specified at the time of message production.

Headers are transparent blobs of data that are stored along with each message.

ConsumerMessage inteface serves as the point of entry where messages read from underlying storage engine can be inspected for metadata and their corresponding metadata be injected back into `context.Context`.

ProducerMessage interface abstracts away the various touch-points between dd-streams and messages produced to the underlying storage.