new method emitMessage() in Kafka Operator

[Chaitanya Chebolu]

Hi All,

  I am proposing to add new API in 0.8 version of
AbstractKafkaInputOperator:
void emitMessage(KafkaMessage message).

  "message" has details like offset, kafkapartition, value of the message.

By adding this, users have more control over the message.  Callback of this
method would be in emitTuples() API.

   To maintain backward compatibility, definition of this new method as
below:

void emitMessage(KafkaMessage message)
{
    emitTuple(message.msg);
}

   Please share your thoughts on this approach.

Regards,
Chaitanya