| ⇢ | A | Subscription added | |
| D | ↘ | F | MessagesHandler got worse | 
| ⇢ | A | get_firebase_playback() added | |
| ⇢ | A | MessagesHandler.notify_offline() added | |
| ⇢ | A | TornadoHandler.http_client() added | |
| ⇢ | A | MessagesHandler.post_firebase() added | |
| ⇢ | A | MessagesHandler.on_reply() added | |
| ⇢ | A | register_subscription() added | |
| ⇢ | A | get_service_worker() added | |
| ⇢ | A | MessagesHandler.http_client() added | |
| A | ↘ | B | UrlCache.get_md5() got worse | 
| A | ↛ | dummy_worker() removed |