presto-redis/src/main/java/io/prestosql/plugin/redis/RedisRecordCursor.java/RedisRecordCursor/hasUnscannedData
class RedisRecordCursor:    public boolean hasUnscannedData()
    {
        if (redisCursor == null) {
            return false;
        }
        // no more keys are unscanned when
        // when redis scan command
        // returns 0 string cursor
        return (!redisCursor.getStringCursor().equals("0"));
    }