code: def test_normalize_empty_tags():
      sentences = [
          [(word[0], (word[1],)) for word in zip(*sentence)]
          for sentence in zip(WORDS, NONE_BIO)
      ]
      new_sentences = utils.normalize_empty_tags(sentences)
      expected = [
          [(word[0], (word[1],)) for word in zip(*sentence)]
          for sentence in zip(WORDS, EMPTY_BIO)
      ]
      assert new_sentences == expected
  
file_path: stanza/stanza/tests/ner/test_ner_utils.py
imports: import pytest
  from stanza.tests import *
  from stanza.models.common.vocab import EMPTY
  from stanza.models.ner import utils
label_desc: Use image node_id 1 for calling a global function with example usage: test_normalize_empty_tags() without return types