code: def backend(cls):
      return Backend.GLOO
  
imports: import datetime
  import logging
  import os
  import shutil
  import time
  import numpy
  import pygloo
  import ray
  from ray._private import ray_constants
  from ray.util.collective.collective_group import gloo_util
  from ray.util.collective.collective_group.base_collective_group import BaseGroup
  from ray.util.collective.const import get_store_name
  from ray.util.collective.types import AllGatherOptions, AllReduceOptions, Backend, BarrierOptions, BroadcastOptions, RecvOptions, ReduceOptions, ReduceScatterOptions, SendOptions
label_desc: Use image node_id 3 for calling the GLOOGroup obj's underlying member method code with example usage: obj.backend(cls) and returns: Backend