code: def get_crime_categories(self, date=None):
          
  
          return sorted(self._get_crime_categories(date=date).values(),
                        key=lambda c: c.name)
docs: Get a list of crime categories, valid for a particular date. Uses the
          crime-categories_ API call.
  
          .. _crime-categories:
              https://data.police.uk/docs/method/crime-categories/
  
          :rtype: list
          :param date: The date of the crime categories to get.
          :type date: str or None
          :return: A ``list`` of crime categories which are valid at the
                   specified date (or at the latest date, if ``None``).