#### Setting headers on messages

Messages sent over the event bus can also contain headers.

This can be specified by setting options when sending or publishing:

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

On the other side, a consumer can retrieve the headers as follows:

    vertx.eventBus().consumer("news.uk.sport",  { e ->
     println e.headers()["some-header"];
    });