code: def _read_country_names(self, countries_file=None):
          
          if not countries_file:
              countries_file = os.path.join(os.path.dirname(__file__), self.COUNTRY_FILE_DEFAULT)
          with open(countries_file) as f:
              countries_json = f.read()
  
          return json.loads(countries_json)
docs: Read list of countries from specified country file or default file.