// List every valid (direct) state transition.
    assertLessThan(NEW, STARTING);
    assertLessThan(NEW, TERMINATED);

    assertLessThan(STARTING, RUNNING);
    assertLessThan(STARTING, STOPPING);
    assertLessThan(STARTING, FAILED);

    assertLessThan(RUNNING, STOPPING);
    assertLessThan(RUNNING, FAILED);

    assertLessThan(STOPPING, FAILED);
    assertLessThan(STOPPING, TERMINATED);
  }