#### 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 `DeliveryOptions` object when sending or publishing:

    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:

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