code: def test_get_collective_group_size(ray_start_single_node_2_gpus):
      world_size = 2
      actors, _ = create_collective_workers(world_size)
      actor0_world_size = ray.get(actors[0].report_world_size.remote())
      actor1_world_size = ray.get(actors[1].report_world_size.remote())
      assert actor0_world_size == actor1_world_size == world_size
  
file_path: ray/python/ray/util/collective/tests/single_node_gpu_tests/test_basic_apis.py
imports: import pytest
  import ray
  from ray.util.collective.tests.util import Worker, create_collective_workers
label_desc: Use image node_id 4 for calling a global function with example usage: test_get_collective_group_size(ray_start_single_node_2_gpus) without return types