@Test
  public void testClientsConnectedToEmptyServer() {
    Integer PORT1 = server
        .invoke(() -> ClientToServerDeltaDUnitTest.createServerCache(Boolean.FALSE, Boolean.TRUE));

    server2
        .invoke(() -> ClientToServerDeltaDUnitTest.createServerCache(Boolean.FALSE, Boolean.FALSE));

    client.invoke(() -> ClientToServerDeltaDUnitTest.createClientCache(
        NetworkUtils.getServerHostName(server.getHost()), new Integer(PORT1), Boolean.TRUE,
        Boolean.TRUE, Boolean.FALSE));

    client2.invoke(() -> ClientToServerDeltaDUnitTest.createClientCache(
        NetworkUtils.getServerHostName(server.getHost()), new Integer(PORT1), Boolean.TRUE,
        Boolean.FALSE, Boolean.FALSE));

    int deltaSent =
        server2.invoke(ClientToServerDeltaDUnitTest::putsWhichReturnsDeltaSent);

    client.invoke(ClientToServerDeltaDUnitTest::waitForLastKey);
    client.invoke(ClientToServerDeltaDUnitTest::checkForDelta);

    client2.invoke(ClientToServerDeltaDUnitTest::waitForLastKey);
    client2.invoke(() -> ClientToServerDeltaDUnitTest.checkDeltaInvoked(deltaSent));
  }
This test does verifies that server with empty data policy sends deltas to the client which can
handle deltas. Server sends full values which can not handle deltas.
geode-cq/src/distributedTest/java/org/apache/geode/internal/cache/tier/sockets/ClientToServerDeltaDUnitTest.java