diff --git a/stanza/models/common/doc.py b/stanza/models/common/doc.py
index <HASH>..<HASH> 100644
--- a/stanza/models/common/doc.py
+++ b/stanza/models/common/doc.py
@@ -309,13 +309,13 @@ class Document(StanzaObject):
     def __repr__(self):
         return json.dumps(self.to_dict(), indent=2, ensure_ascii=False)
 
-    def to_serialized_string(self):
+    def to_serialized(self):
         """ Dumps the whole document including text to a byte array containing a list of list of dictionaries for each token in each sentence in the doc.
         """
         return pickle.dumps((self.text, self.to_dict()))
 
     @classmethod
-    def from_serialized_string(cls, serialized_string):
+    def from_serialized(cls, serialized_string):
         """ Create and initialize a new document from a serialized string generated by Document.to_serialized_string():
         """
         try:
@@ -639,7 +639,7 @@ class Token(StanzaObject):
             ret.append(token_dict)
         for word in self.words:
             word_dict = word.to_dict()
-            if NER in fields and len(self.id) == 1: # propagate NER label to Word if it is a single-word token
+            if len(self.id) == 1 and NER in fields and getattr(self, NER) is not None: # propagate NER label to Word if it is a single-word token
                 word_dict[NER] = getattr(self, NER)
             ret.append(word_dict)
         return ret
rename function & fix ner tag is none bug