@After
  public void postCheck() {
    Assert.assertFalse("Router should be closed at the end of each test", router.isOpen());
    Assert.assertEquals("Router operations count must be zero", 0, router.getOperationsCount());
    if (cryptoJobHandler != null) {
      cryptoJobHandler.close();
    }
  }
Every test in this class should leave the router closed in the end. Some tests do additional checks after
closing the router. This is just a guard to ensure that the tests are not broken (which helped when developing
these tests).
ambry-router/src/test/java/com/github/ambry/router/GetManagerTest.java