code: def ray_start_single_node_2_gpus():
      # Please start this fixture in a cluster with 2 GPUs.
      address_info = ray.init(num_gpus=2)
      yield address_info
      ray.shutdown()
  
file_path: ray/python/ray/util/collective/tests/conftest.py
imports: import logging
  import pytest
  import ray
  from ray.util.collective.collective_group.nccl_collective_group import _get_comm_key_from_devices, _get_comm_key_send_recv
  from ray.util.collective.const import get_store_name
label_desc: Use image node_id 2 for calling a global function with example usage: ray_start_single_node_2_gpus() without return types