public static void checkDeltaFeatureNotUsed() {
    assertTrue("Delta Propagation feature used.", !(DeltaTestImpl.deltaFeatureUsed()));
  }
This test ensures that a server sends delta bytes to a client even if that client is not
interested in that event but is getting the event only because the event satisfies a CQ which
the client has registered with the server.
geode-cq/src/distributedTest/java/org/apache/geode/internal/cache/tier/sockets/ClientToServerDeltaDUnitTest.java