Failure in frequent_strings_sketch_build()

[nikunjbhartia]

SELECT
bqutil.datasketches.frequent_strings_sketch_build(file_extension, 1, 5) as extensions_fi_sketch
FROM (
SELECT
REGEXP_EXTRACT(path, r'.([^.]+)$') AS file_extension,
FROM bigquery-public-data.github_repos.files )

Error:

ReferenceError: sketch is not defined at bqutil.datasketches.frequent_strings_sketch_build(STRING, INT64, INT64) line 34, columns 27-28

Issue: sketch referenced without state.
https://github.com/apache/datasketches-bigquery/blob/main/fi/sqlx/frequent_strings_sketch_build.sqlx#L64C7-L64C38

[nikunjbhartia]

same issue with frequent_strings_sketch_merge()