code: def cpu_instance_type():
      return "ml.m5.xlarge"
  
imports: from __future__ import absolute_import
  import logging
  import json
  import os
  from packaging import version
  import pytest
  from mock import MagicMock, Mock, patch
  from sagemaker import image_uris
  from sagemaker.session_settings import SessionSettings
  from sagemaker.tensorflow import TensorFlow, TrainingCompilerConfig
  from tests.unit.sagemaker.training_compiler import EC2_GPU_INSTANCE_CLASSES
label_desc: Use image node_id 2 for calling a global function with example usage: cpu_instance_type() and returns: str