private void performBulkLoad(String keyPrefix) throws IOException {
    FileSystem fs = TEST_UTIL.getTestFileSystem();
    Path baseDirectory = TEST_UTIL.getDataTestDirOnTestFS(TEST_NAME);
    Path hfilePath =
      new Path(baseDirectory, Bytes.toString(famName) + Path.SEPARATOR + "hfile_" + keyPrefix);

    HFileTestUtil.createHFile(TEST_UTIL.getConfiguration(), fs, hfilePath, famName, qualName,
      Bytes.toBytes(keyPrefix), Bytes.toBytes(keyPrefix + "z"), ROWS_IN_BULK_LOAD);

    Map<BulkLoadHFiles.LoadQueueItem, ByteBuffer> result =
      BulkLoadHFiles.create(TEST_UTIL.getConfiguration()).bulkLoad(table1, baseDirectory);
    assertFalse(result.isEmpty());
  }
This test checks whether backups properly track & manage bulk files loads.
hbase-backup/src/test/java/org/apache/hadoop/hbase/backup/TestIncrementalBackupWithBulkLoad.java