code: def ray_start_8_cpus():
      address_info = ray.init(num_cpus=8)
      yield address_info
      # The code after the yield will run as teardown code.
      ray.shutdown()
  
imports: import math
  import lightgbm
  import pandas
  import pytest
  from sklearn.datasets import load_breast_cancer
  from sklearn.model_selection import train_test_split
  import ray
  from ray import tune
  from ray.train import ScalingConfig
  from ray.train.constants import TRAIN_DATASET_KEY
  from ray.train.lightgbm import LightGBMTrainer
label_desc: Use image node_id 2 for calling a global function with example usage: ray_start_8_cpus() without return types