private void executeTask(Runnable task) {
    try {
      executorService.get().execute(task);
    } catch (RejectedExecutionException ignored) {
      // Ignore, we are getting shutdown
    }
  }
This method will be invoked whenever a member stops being a managing node. The
{@code ManagementException} has to be handled by the caller.
geode-core/src/main/java/org/apache/geode/management/internal/FederatingManager.java