Return filters from query string.

        :return list: filter information

def filters(self):
        """Return filters from query string.

        :return list: filter information
        """
        results = []
        filters = self.qs.get('filter')
        if filters is not None:
            try:
                results.extend(json.loads(filters))
            except (ValueError, TypeError):
                raise InvalidFilters("Parse error")
        if self._get_key_values('filter['):
            results.extend(self._simple_filters(self._get_key_values('filter[')))
        return results