Convenience method to create a Query with the Index's fields.

        Args:
            fields (iterable, optional): The fields to include in the Query,
                defaults to the Index's `all_fields`.

        Returns:
            Query: With the specified fields or all the fields in the Index.

def create_query(self, fields=None):
        """Convenience method to create a Query with the Index's fields.

        Args:
            fields (iterable, optional): The fields to include in the Query,
                defaults to the Index's `all_fields`.

        Returns:
            Query: With the specified fields or all the fields in the Index.
        """
        if fields is None:
            return Query(self.fields)

        non_contained_fields = set(fields) - set(self.fields)
        if non_contained_fields:
            raise BaseLunrException(
                "Fields {} are not part of the index", non_contained_fields
            )

        return Query(fields)