public void removePost(Post post) {
em.remove(post);
}
public Like like(User user, Post post) {
Like like = new Like();
like.setPost(post);
like.setUser(user);
like.setTimestamp(new Date());
em.persist(like);
// post likes
Set<Like> likes = post.getLikes();
if (likes == null) {
likes = new HashSet<Like>();