code: def setup_module():
      global _cluster
      global _client
      global _visible_devices
      if not _is_single_gpu:
          (_client, _cluster) = start_dask_client()
          _visible_devices = _client.scheduler_info()["workers"]
  
file_path: cugraph/python/cugraph/cugraph/tests/generators/test_rmat_mg.py
imports: import pytest
  import dask_cudf
  import cugraph
  from cugraph.generators import rmat
  from cugraph.testing.mg_utils import start_dask_client, stop_dask_client
  from cugraph.dask.common.mg_utils import is_single_gpu
label_desc: Use image node_id 2 for calling a global function with example usage: setup_module() without return types