code: def real_main(start_url=None,
                ignore_prefixes=None,
                upload_build_id=None,
                upload_release_name=None):
      
      coordinator = workers.get_coordinator()
      fetch_worker.register(coordinator)
      coordinator.start()
  
      item = SiteDiff(
          start_url=start_url,
          ignore_prefixes=ignore_prefixes,
          upload_build_id=upload_build_id,
          upload_release_name=upload_release_name,
          heartbeat=workers.PrintWorkflow)
      item.root = True
  
      coordinator.input_queue.put(item)
      coordinator.wait_one()
      coordinator.stop()
      coordinator.join()
docs: Runs the site_diff.