@Override
  public int positionedRead(long position, byte[] buffer, int offset, int length)
      throws IOException {
    seek(position);
    return read(buffer, offset, length);
  }
@Test
  public void positionedReadMulti() throws IOException, AlluxioException {
    AlluxioURI ufsPath = getUfsPath();
    createFile(ufsPath, CHUNK_SIZE);
    Random random = new Random();
    try (FileInStream inStream = getStream(ufsPath)) {
      for (int i = 0; i < 10; i++) {
        int pos = random.nextInt(CHUNK_SIZE);
        int len = CHUNK_SIZE - pos;
        byte[] res = new byte[len];
        assertEquals(len,
            inStream.positionedRead(pos, res, 0, len));
        assertTrue(BufferUtils.equalIncreasingByteArray(pos, len, res));
      }
    }
  }