@Override
  public Properties getDistributedSystemProperties() {
    Properties result = super.getDistributedSystemProperties();
    result.put(ConfigurationProperties.SERIALIZABLE_OBJECT_FILTER,
        "org.apache.geode.internal.cache.execute.**;org.apache.geode.test.dunit.**");
    return result;
  }
Return the number of members the function is expected to execute on
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/execute/FunctionServiceBase.java