Parses the `id` filter paramter from the url query.

def _get_filter_ids(cls, request):
        """Parses the `id` filter paramter from the url query.
        """
        id_query = request.url.query.get('id', None)

        if id_query is None:
            return None

        filter_ids = id_query.split(',')
        for filter_id in filter_ids:
            cls._validate_id(filter_id)

        return filter_ids