text: import pytest
  from spacy.language import Language
  from spacy.lang.punctuation import TOKENIZER_INFIXES
  from spacy.lang.char_classes import ALPHA
  
  
  @pytest.mark.parametrize(
      "text,expected_tokens", [("l'avion", ["l'", "avion"]), ("j'ai", ["j'", "ai"])]
  )
  def test_issue768(text, expected_tokens):
      """Allow zero-width 'infix' token during the tokenization process."""
      SPLIT_INFIX = r"(?<=[{a}]\')(?=[{a}])".format(a=ALPHA)
  
      class FrenchTest(Language):
          class Defaults(Language.Defaults):
              infixes = TOKENIZER_INFIXES + [SPLIT_INFIX]
  
      fr_tokenizer_w_infix = FrenchTest().tokenizer
      tokens = fr_tokenizer_w_infix(text)
      assert len(tokens) == 2
      assert [t.text for t in tokens] == expected_tokens
  