public static void verifyDeltaReceiverStats(Integer path, Long expectedDeltasProcessed,
      Long expectedDeltaFailures) {
    long numOfDeltasProcessed = 0;
    long deltaTime = 0;
    long deltaFailures = 0;
    if (path == PEER_TO_PEER || path == CLIENT_TO_SERVER || path == SERVER_TO_CLIENT) {
      CachePerfStats stats = ((DistributedRegion) cache.getRegion(REGION_NAME)).getCachePerfStats();

      numOfDeltasProcessed = stats.getDeltaUpdates();
      deltaTime = stats.getDeltaUpdatesTime();
      deltaFailures = stats.getDeltaFailedUpdates();
    } else {
      fail("Invalid path code for delta propagation: " + path);
    }
    assertTrue("Number of deltas received was expected to be " + expectedDeltasProcessed
        + " but is " + numOfDeltasProcessed, numOfDeltasProcessed == expectedDeltasProcessed);

    // It is possible for deltaTime to be zero depending on the system clock
    // resolution
    assertTrue("Delta calculation is expected to be >= zero but was " + deltaTime, deltaTime >= 0);

    assertTrue("Number of delta failures was expected to be " + expectedDeltaFailures + " but is "
        + deltaFailures, deltaFailures == expectedDeltaFailures);
  }
Simulates old value null, entry null
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/DeltaPropagationStatsDUnitTest.java