new_contents: import pytest
  parametrize = pytest.mark.parametrize
  
  from git_lang_guesser import guess_lang
  
  LANGUAGE = "language"
  
  
  exampleData = [
      {LANGUAGE: "HTML"},
      {LANGUAGE: "Java"},
      {LANGUAGE: "Python"},
      {LANGUAGE: "Python"},
      {LANGUAGE: "C"},
  ]
  expectedCount = {
      "HTML": 1,
      "Java": 1,
      "Python": 2,
      "C": 1,
  }
  expectedFavourite = "Python"
  
  
  class TestCountLanguages(object):
      def test_basic(self):
          """Ensure basic usage does the right thing"""
          counter = guess_lang.count_languages(exampleData)
          assert(dict(counter) == expectedCount)
  
      def test_empty(self):
          """Ensure we can an empty repository list"""
          counter = guess_lang.count_languages([])
          assert(dict(counter) == {})
  
      @parametrize('filter_none, expected', [(True, {}), (False, {None: 1})])
      def test_none(self, filter_none, expected):
          """Test that filter_none works"""
          counter = guess_lang.count_languages([{LANGUAGE: None}], filter_none=filter_none)
          assert(dict(counter) == expected)
  
      def test_language_missing(self):
          """Ensure we can handle a repository with language missing"""
          counter = guess_lang.count_languages([{LANGUAGE: "Python"}, {}])
          assert(dict(counter) == {"Python": 1})
  
  
  class TestGuessFavourite(object):
      def test_basic(self):
          """Ensure basic usage does the right thing"""
          favourite = guess_lang.guess_favourite(exampleData)
          assert(favourite == expectedFavourite)
  
      def test_empty(self):
          """Ensure we can an empty repository list"""
          favourite = guess_lang.guess_favourite([])
          assert(favourite is None)
subject: Add tests for guess_lang