title: what does JhiEventManager do?
body: <p>I Am building an angularJS5 client using <strong>jhipster client</strong> and I encountered '<em>JhiEventManage</em>r' in login typescript file.</p>
  
  <pre><code>import { JhiEventManager } from 'ng-jhipster';
  .....
   constructor(
          private eventManager: JhiEventManager,
  ...
  }
  ...
  ...
  this.eventManager.broadcast({
        name: 'authenticationSuccess',
        content: 'Sending Authentication Success'
  });
  </code></pre>
  
  <p>I just want to know what is the purpose of JhiEventManager and how can I make use of it for other functionality? Is there any help or tutorial docs available?</p>