def _validate_filter_fields(self, filter_by):
        """
        :param filter_by: dict
        :raises: pybomb.exceptions.InvalidFilterFieldException
        """
        for filter_field in filter_by:
            if (
                filter_field not in self.RESPONSE_FIELD_MAP
                or not self.RESPONSE_FIELD_MAP[filter_field].is_filter
            ):
                raise InvalidFilterFieldException(
                    '"{0}" is an invalid filter field'.format(filter_field)
                )