def get_crime_categories(self, date=None):
        """
        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``).
        """

        return sorted(self._get_crime_categories(date=date).values(),
                      key=lambda c: c.name)