enrich() and ExchangeSentEvents

Hi,

I'm playing with Camel 2.12 and the event notification system and
discovered a difference in behavior using enrich() as opposed to
inOnly()/inOut() wrt events sent out.

When using inOnly() or inOut() in the example below I see an
ExchangeSendingEvent and an ExchangeSentEvent when sending/receiving to the
activemq endpoint.

However, and this is confusing, when using enrich() neither
ExchangeSendingEvent nor ExchangeSentEvent is produced.

Is this by purpose or a bug?

Kind regards,
Jörn

Example route:

from("direct:start")
.enrich("activemq:enricher")
// .inOnly("activemq:enricher")
// .inOut("activemq:enricher")
.to("mock:end");

from("activemq:enricher")
.setBody(simple("Hello, ${body}!"));