public void When_publishing_should_clone_headers()
        {
            var publishPipeline = new FakePipeline <IOutgoingPublishContext>();
            var context         = CreateContext(publishPipeline);
            var publishOptions  = new PublishOptions();

            publishOptions.SetHeader("header1", "header1 value");

            MessageOperations.Publish <MyMessage>(context, m => { }, publishOptions);
            publishPipeline.ReceivedContext.Headers.Add("header2", "header2 value");
            publishPipeline.ReceivedContext.Headers["header1"] = "updated header1 value";

            var optionsHeaders = publishOptions.GetHeaders();

            Assert.AreEqual(1, optionsHeaders.Count);
            Assert.AreEqual("header1 value", optionsHeaders["header1"]);
        }