@Before
  public void setUp() throws Exception {
    server1 = getVM(0);
    server2 = getVM(2);

    regionName = getClass().getSimpleName() + "_" + testName.getMethodName();

    server1.invoke(this::createServerCache);
    server2.invoke(this::createServerCache);
  }
Test delta propagation for faulty delta implementation

<p>
TRAC #40396: Need better error messages (and unit tests) when users code delta propagation
methods incorrectly

@since GemFire 6.1
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/tier/DeltaPropagationFailureRegressionTest.java