+            if self.persist != PersistMethod.none:
+                window = deque(maxlen=PERSISTENCE_RADIUS)
+
+                if self.persist == PersistMethod.sequence:
+                    state = mwpersistence.DiffState(SequenceMatcher(tokenizer = wikitext_split),
+                                                    revert_radius=PERSISTENCE_RADIUS)
+
+                elif self.persist == PersistMethod.segment:
+                    state = mwpersistence.DiffState(SegmentMatcher(tokenizer = wikitext_split),
+                                                    revert_radius=PERSISTENCE_RADIUS)
+
+                # self.persist == PersistMethod.legacy
+                else:
+                    from mw.lib import persistence
+                    state = persistence.State()
+
+                
+