@Test public void testRandomOrderOneElement(){
  RandomOrderController roc=new RandomOrderController();
  roc.addTestElement(new TestSampler("zero"));
  TestElement sampler=null;
  List usedSamplers=new ArrayList<>();
  roc.initialize();
  while ((sampler=roc.next()) != null) {
    String samplerName=sampler.getName();
    if (usedSamplers.contains(samplerName)) {
      assertTrue("Duplicate sampler returned from next()",false);
    }
    usedSamplers.add(samplerName);
  }
  assertEquals("All samplers were returned",1,usedSamplers.size());
}