JMSXGroupID clustered message grouping

Hi,

When using multiple partitions and consumers, can Kafka ensure that JMS
messages with the same JMSXGroupID are handled by the same consumer? Or
does this have to be implemented when writing the Producers and Consumers?

For reference, this is in comparison to the clustered message grouping
feature provided by HornetQ:
http://docs.jboss.org/hornetq/2.4.0.Final/docs/user-manual/html/message-grouping.html
"Message groups are useful when you want all messages for a certain value
of the property to be processed serially by the same consumer."

Thanks

Andrew