title: How to collect multiple lists to one list with java-streams?
body: <p>How can I collect multiple <code>List</code> values into one list, using <code>java-streams</code>?</p>
  
  <pre><code>List&lt;MyListService&gt; services;
  
  services.stream().XXX.collect(Collectors.toList());
  
  
  interface MyListService {
     List&lt;MyObject&gt; getObjects();
  }
  </code></pre>
  
  <p>As I have full control over the interface: or should I change the method to return an <strong>Array</strong> instead of a List?</p>