@Before
  public void before() {
    locator = getVM(0);
    sender = getVM(1);
    receiver = getVM(2);
  }
It would be nice if this test didn't need to use the cache since the test's purpose is to test
that the {@link Connection} class can be closed while readers and writers hold locks on its
internal TLS {@link ByteBuffer}s

But this test does use the cache (region) because it enabled us to use existing cache messaging
and to use the DistributionMessageObserver (observer) hooks.

see also ClusterCommunicationsDUnitTest
geode-core/src/distributedTest/java/org/apache/geode/internal/tcp/ConnectionCloseSSLTLSDUnitTest.java