presto-hive/src/main/java/io/prestosql/plugin/hive/BackgroundHiveSplitLoader.java/BackgroundHiveSplitLoader/getBucketNumber
class BackgroundHiveSplitLoader:    @VisibleForTesting
    static OptionalInt getBucketNumber(String name)
    {
        for (Pattern pattern : BUCKET_PATTERNS) {
            Matcher matcher = pattern.matcher(name);
            if (matcher.matches()) {
                return OptionalInt.of(parseInt(matcher.group(1)));
            }
        }
        return OptionalInt.empty();
    }