code: def test_matcher_no_zero_length(en_vocab):
      doc = Doc(en_vocab, words=["a", "b"], tags=["A", "B"])
      matcher = Matcher(en_vocab)
      matcher.add("TEST", [[{"TAG": "C", "OP": "?"}]])
      assert len(matcher(doc)) == 0
  
imports: import pytest
  from mock import Mock
  from spacy.matcher import Matcher
  from spacy.tokens import Doc, Span, Token
  from ..doc.test_underscore import clean_underscore
label_desc: Use image node_id 49 for calling a global function with example usage: test_matcher_no_zero_length(en_vocab) without return types