@Test
public void testSelectRuncContainerTypeWithDefaultSet() {

  Map<String, String> envRuncType = new HashMap<>();
  Map<String, String> envOtherType = new HashMap<>();
  conf.set(YarnConfiguration.LINUX_CONTAINER_RUNTIME_TYPE, "default");
  envRuncType.put(ContainerRuntimeConstants.ENV_CONTAINER_TYPE,
      ContainerRuntimeConstants.CONTAINER_RUNTIME_RUNC);
  envOtherType.put(ContainerRuntimeConstants.ENV_CONTAINER_TYPE, "other");
  Assert.assertFalse(RuncContainerRuntime
      .isRuncContainerRequested(conf, null));
  Assert.assertTrue(RuncContainerRuntime
      .isRuncContainerRequested(conf, envRuncType));
  Assert.assertFalse(RuncContainerRuntime
      .isRuncContainerRequested(conf, envOtherType));
}