new_contents: from unittest.mock import PropertyMock, patch
  
  import api as api_test
  import requests
  
  from memsource import api, constants, models
  
  
  class TestApiLanguage(api_test.ApiTestCase):
      def setUp(self):
          self.url_base = 'https://cloud.memsource.com/web/api/v2/language'
          self.language = api.Language(None)
  
      @patch.object(requests.Session, 'request')
      def test_list(self, mock_request):
          type(mock_request()).status_code = PropertyMock(return_value=200)
  
          mock_request().json.return_value = [
              {
                  "name": "Abkhaz",
                  "code": "ab"
              },
              {
                  "name": "Afar",
                  "code": "aa"
              }
          ]
  
          for language in self.language.listSupportedLangs():
              self.assertIsInstance(language, models.Language)
  
          mock_request.assert_called_with(
              constants.HttpMethod.post.value,
              '{}/listSupportedLangs'.format(self.url_base),
              data={
                  'token': self.language.token,
              },
              timeout=constants.Base.timeout.value
          )
  
subject: Add test_language.py