### Question:
BackgroundHiveSplitLoader implements HiveSplitLoader { public static boolean hasAttemptId(String bucketFilename) { Matcher matcher = BUCKET_WITH_OPTIONAL_ATTEMPT_ID_PATTERN.matcher(bucketFilename); return matcher.matches() && matcher.group(2) != null; } BackgroundHiveSplitLoader(
            Table table,
            Iterable<HivePartitionMetadata> partitions,
            TupleDomain<? extends ColumnHandle> compactEffectivePredicate,
            DynamicFilter dynamicFilter,
            Duration dynamicFilteringProbeBlockingTimeout,
            TypeManager typeManager,
            Optional<BucketSplitInfo> tableBucketInfo,
            ConnectorSession session,
            HdfsEnvironment hdfsEnvironment,
            NamenodeStats namenodeStats,
            DirectoryLister directoryLister,
            Executor executor,
            int loaderConcurrency,
            boolean recursiveDirWalkerEnabled,
            boolean ignoreAbsentPartitions,
            Optional<ValidWriteIdList> validWriteIds); @Override void start(HiveSplitSource splitSource); @Override void stop(); static boolean hasAttemptId(String bucketFilename);  }### Answer:
@Test public void testGetAttemptId() { assertFalse(hasAttemptId("bucket_00000")); assertTrue(hasAttemptId("bucket_00000_0")); assertTrue(hasAttemptId("bucket_00000_10")); assertTrue(hasAttemptId("bucket_00000_1000")); assertFalse(hasAttemptId("bucket_00000__1000")); assertFalse(hasAttemptId("bucket_00000_a")); assertFalse(hasAttemptId("bucket_00000_ad")); assertFalse(hasAttemptId("base_00000_00")); }