@VisibleForTesting
  <R> List<R> cleanResults(List<?> functionResults) {
    List<R> results = new ArrayList<>();
    for (Object functionResult : functionResults) {
      if (functionResult == null) {
        continue;
      }
      if (functionResult instanceof Throwable) {
        // log the exception and continue
        logger.warn("Error executing CacheRealizationFunction.", (Throwable) functionResult);
        continue;
      }
      results.add((R) functionResult);
    }
    return results;
  }
each locator will have one instance of this running if enabled
geode-core/src/main/java/org/apache/geode/management/internal/api/LocatorClusterManagementService.java