title: Can RealmCollectionChange be used as a way of syncing data back to server?
body: <p>I noticed that in Realm Swift, there is a RealmCollectionChange
  <a href="https://realm.io/docs/swift/latest/#realm-notifications" rel="nofollow">https://realm.io/docs/swift/latest/#realm-notifications</a></p>
  
  <p>It seems to contain the objects that have changed. Can I use that notification block to add code to sync the data back to a back end database?
  Is the notification block running on the main queue?</p>