@Override
  public Coder<SqsCheckpointMark> getCheckpointMarkCoder() {
    return SerializableCoder.of(SqsCheckpointMark.class);
  }
@Test
  public void testCheckpointCoderIsSane() {
    final AmazonSQS client = embeddedSqsRestServer.getClient();
    final String queueUrl = embeddedSqsRestServer.getQueueUrl();
    client.sendMessage(queueUrl, DATA);
    SqsUnboundedSource source =
        new SqsUnboundedSource(
            SqsIO.read().withQueueUrl(queueUrl).withMaxNumRecords(1),
            new SqsConfiguration(pipeline.getOptions().as(AwsOptions.class)),
            SqsMessageCoder.of());
    CoderProperties.coderSerializable(source.getCheckpointMarkCoder());
  }