code: def test_initial_workers(shutdown_only):
      # `num_cpus` should be <=2 because a Travis CI machine only has 2 CPU cores
      ray.init(num_cpus=1, include_dashboard=True)
      wait_for_condition(lambda: len(get_workers()) == 1)
  
file_path: ray/python/ray/tests/test_multi_tenancy.py
imports: import os
  import sys
  import time
  import pytest
  import numpy
  import ray
  from ray.core.generated import common_pb2
  from ray.core.generated import node_manager_pb2, node_manager_pb2_grpc
  from ray._private.test_utils import wait_for_condition, run_string_as_driver, run_string_as_driver_nonblocking
  from ray._private.utils import init_grpc_channel
label_desc: Use image node_id 2 for calling a global function with example usage: test_initial_workers(shutdown_only) without return types