@Test
  public void newContainersShouldShareDataAccess() throws Exception {
    manager.startAllInactiveContainers();
    await().until(() -> {
      ServerContainer container = manager.getContainer(0);
      return container.getState().isStarted();
    });

    String key = "value_testSessionAdd";
    String value = "Foo";

    client.setPort(Integer.parseInt(manager.getContainerPort(0)));
    Client.Response resp = client.set(key, value);

    await().untilAsserted(() -> getKeyValueDataOnAllClients(key, value, resp.getSessionCookie()));
    int numContainers = manager.numContainers();
    // Add and start new container
    manager.addContainer(install);
    customizeContainers();

    manager.startAllInactiveContainers();
    // Check that a container was added
    assertEquals(numContainers + 1, manager.numContainers());
    await().untilAsserted(() -> getKeyValueDataOnAllClients(key, value, resp.getSessionCookie()));
  }
Test that a container added to the system after puts still can access the correct sessions and
data.
geode-assembly/src/distributedTest/java/org/apache/geode/session/tests/CargoTestBase.java