code: def _task_fn(index, driver_addresses, num_hosts, tmout, key):
      task = task_service.HorovodRunTaskService(index, key)
      try:
          driver = driver_service.HorovodRunDriverClient(
              driver_addresses, key
          )
          driver.register_task(
              index, task.addresses(), host_hash.host_hash()
          )
          task.wait_for_initial_registration(tmout)
          # Tasks ping each other in a circular fashion to determine interfaces
          # reachable within the cluster.
          next_task_index = (index + 1) % num_hosts
          next_task_addresses = driver.all_task_addresses(
              next_task_index
          )
          # We request interface matching to weed out all the NAT'ed interfaces.
          next_task = task_service.HorovodRunTaskClient(
              next_task_index,
              next_task_addresses,
              key,
              match_intf=True,
              retries=10,
          )
          driver.register_task_to_task_addresses(
              next_task_index, next_task.addresses()
          )
          # Notify the next task that the address checks are completed.
          next_task.task_to_task_address_check_completed()
          # Wait to get a notification from previous task that its address checks
          # are completed as well.
          task.wait_for_task_to_task_address_check_finish_signal(tmout)
  
      finally:
          task.shutdown()
  
imports: import sys
  from bluefog.run.horovodrun.common.util import codec, host_hash
  from bluefog.run.horovodrun.driver import driver_service
  from bluefog.run.horovodrun.task import task_service
label_desc: Use image node_id 1 for calling a global function with example usage: _task_fn(index, driver_addresses, num_hosts, tmout, key) without return types