==== Setting headers on messages

Messages sent over the event bus can also contain headers.

This can be specified by providing a `headers` object
inside the `link:../../vertx-core/dataobjects.html#DeliveryOptions[DeliveryOptions]` object when sending or publishing:

[source,javascript]
----
var options = {
 headers: {
   "some-header" : "some-value"
 }
}
vertx.eventBus().send("news.uk.sport", "Yay! Someone kicked a ball", options);
----

On the other side, the consumer can retrieve the message header as follows:

[source, javascript]
----
vertx.eventBus().consumer("news.uk.sport", function(e) {
 console.log(e.headers().get("some-header"));
});
----