title: How to write tests for tracking event flows in eventbus?
body: <p><strong>Long description:</strong>
  In our gwt with mvp4g app we have pretty complicated flow of events in eventbus. One event like LOGIN produces multiple others as a reaction from presenters/handlers. Currently we have great difficulties with understanding how events interrelated i.e. which events must follow this particular one.<br>
  We have tests for presenters and views, but we are lacking tests which would clearly show/model event flows, preferably without usage of real views and services.</p>
  
  <p><strong>Short description:</strong>
  New tests on eventBus(?) should be developed which should clearly describe and test event flows.</p>
  
  <p>I have few rud ideas but they all sounds not satisfactory:</p>
  
  <ol>
  <li><p>Write custom implementation(could be ugly) of mvp4g eventbus and:</p>
  
  <ul>
  <li>use real presenters</li>
  <li>use mock(?) views</li>
  <li>mock services</li>
  <li>verify all produced service calls</li>
  <li><strong>Why not cool</strong>: <strong>(a)</strong> In this case test would not verify produced events directly but only that ones which have services. <strong>(b)</strong>
  EventBus implementation would look rather scarry - it must create each presenter with mocked services and views</li>
  </ul></li>
  <li><p>Find a way to use some magical mvp4g mechanism to create eventBus in test and mock vies, services. </p>
  
  <ul>
  <li><strong>Why not cool</strong> : same as prev - only indirect verification through services is possible, and I cannot find how to create eventBus manually and solve all problems with GIN, inter GWT module dependencies and so. I guess there is no simple way to do it.</li>
  </ul></li>
  </ol>
  
  <p>Is there any general solution for problem of tracking event tree in tests? Guess I'm not the first person to stare at complicated eventbus event flows.</p>