public void should_register_and_get_callback()
{
var completionCallbackMock = new Mock<ICompletionCallback>();
var messageId = Guid.NewGuid();
_callbackRepository.RegisterCallback(messageId, completionCallbackMock.Object);
var callback = _callbackRepository.GetCallback(messageId);
Assert.AreEqual(completionCallbackMock.Object, callback);
}