@Test
public void testClobber() throws ClassNotFoundException,
    InstantiationException, IllegalAccessException {

  Context ctx = new Context();
  ctx.put("preserveExisting", "false"); // DEFAULT BEHAVIOR
  Interceptor.Builder builder = InterceptorBuilderFactory.newInstance(
      InterceptorType.TIMESTAMP.toString());
  builder.configure(ctx);
  Interceptor interceptor = builder.build();
  long originalTs = 1L;
  Event event = EventBuilder.withBody("test event", Charsets.UTF_8);
  event.getHeaders().put(Constants.DEFAULT_HEADER_NAME, Long.toString(originalTs));
  Assert.assertEquals(Long.toString(originalTs),
      event.getHeaders().get(Constants.DEFAULT_HEADER_NAME));
  Long now = System.currentTimeMillis();
  event = interceptor.intercept(event);
  String timestampStr = event.getHeaders().get(Constants.DEFAULT_HEADER_NAME);
  Assert.assertNotNull(timestampStr);
  Assert.assertTrue(Long.parseLong(timestampStr) >= now);
}