heart of the application is the
        <a href="#code/src/main/scala/sample/eventuate/OrderManager.scala" class="shortcut">OrderManager</a>.
    It is implemented as
    <a href="http://rbmhtechnology.github.io/eventuate/latest/api/index.html#com.rbmhtechnology.eventuate.EventsourcedView">EventsourcedView</a>
    to better illustrate how orders are created in the distributed system. For the moment
    it is enough to assume that it is a plain actor and its <code>onCommand</code> method is actually the
    