private void testSerTuple(Tuple t, byte[] expected) throws Exception {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    DataOutput out = new DataOutputStream(baos);

    bis.writeDatum(out, t);

    Tuple t2 =
        (Tuple) bis.readDatum(new DataInputStream(new ByteArrayInputStream(baos.toByteArray())));

    assertEquals(t, t2);
  }