private static int vmRemoteLoaderInvokedCount(VM vm) {
    return vm.invoke(SearchAndLoadDUnitTest::fetchRemoteLoaderInvokedCount);
  }
Confirm that a netLoad that returns null will NOT allow other netLoad methods to be called.
geode-core/src/distributedTest/java/org/apache/geode/cache30/SearchAndLoadDUnitTest.java