@Override
    public String getId() {
      return getClass().getName();
    }
This tests make sure that, in case of LonerDistributedSystem we don't get ClassCast Exception.
Just making sure that the function executed on lonerDistributedSystem.

<p>
Regression test for bug: If invoked from LonerDistributedSystem, FunctionService.onMembers()
throws ClassCastException
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/execute/FunctionExecutionOnLonerRegressionTest.java