@Test
  public void testManager() {
    managementTestRule.createMember(memberVMs[0]);
    managementTestRule.createMember(memberVMs[1]);

    managementTestRule.createManager(memberVMs[2], false);

    managementTestRule.createManager(managerVM, false);

    memberVMs[2].invoke(this::startManager);

    // Now start Managing node managerVM. System will have two Managers now which
    // should be OK
    DistributedMember member = managementTestRule.getDistributedMember(memberVMs[2]);
    managementTestRule.startManager(managerVM);

    verifyManagerStarted(managerVM, member);
    managementTestRule.stopManager(managerVM);
  }
Creates and starts a managerVM. Multiple Managers
geode-core/src/distributedTest/java/org/apache/geode/management/CacheManagementDUnitTest.java