@Test
  public void testPrimaryShouldBeNullAndEPListShouldBeEmptyWhenAllServersAreDead()
      throws Exception {
    createClientCache(getName(), NetworkUtils.getServerHostName(server1.getHost()));
    verifyPrimaryShouldNotBeNullAndEPListShouldNotBeEmpty();
    server1.invoke(HAStartupAndFailoverDUnitTest::stopServer);
    server2.invoke(HAStartupAndFailoverDUnitTest::stopServer);
    server3.invoke(HAStartupAndFailoverDUnitTest::stopServer);
    verifyDeadAndLiveServers(3, 0);
    verifyPrimaryShouldBeNullAndEPListShouldBeEmpty();
  }
verify that Primary Should Be Null And EPList Should Be Empty When All Servers Are Dead
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/tier/sockets/HAStartupAndFailoverDUnitTest.java