@Test
public void populatesPostsToEvents() {

    String postId = "postId";
    Post post = mock(Post.class);
    Event event = mock(Event.class);
    when(event.getPostId()).thenReturn(postId);
    EventListFeed feed = new EventListFeed();
    feed.events =  Arrays.asList(event);
    Map<String, Post> postMap = new HashMap<String, Post>();
    postMap.put(postId, post);
    feed.posts = postMap;
    feed.users = new HashMap<>();
    feed.flatten();
    verify(event).setPost(post);
}