@Test
public void testInitializeMissingRuntimeClass() throws Exception {

  conf.set(YarnConfiguration.LINUX_CONTAINER_RUNTIME_ALLOWED_RUNTIMES,
      "mock");
  try {
    delegatingLinuxContainerRuntime.initialize(conf, null);
    fail("initialize should fail");
  } catch (ContainerExecutionException e) {
    assert(e.getMessage().contains("Invalid runtime set"));
  }
}