code: def data_exists(data_dir):
      return os.path.exists(data_dir)
  
file_path: NeMo/tests/collections/nlp/test_pretrained_models_performance.py
imports: import os
  from pathlib import Path
  from shutil import rmtree
  from unittest import TestCase
  import pytest
  import pytorch_lightning
  from omegaconf import OmegaConf
  import nemo.collections.nlp.models
label_desc: Use image node_id 3 for calling a global function with example usage: data_exists(data_dir) and returns: os