code: def add_default_labels(node_info, labels):
      labels["ray.io/node_id"] = node_info["NodeID"]
      return labels
  
file_path: ray/python/ray/tests/test_node_labels.py
imports: import os
  import sys
  import pytest
  import subprocess
  import ray
  from ray.cluster_utils import AutoscalingCluster
  from ray._private.test_utils import wait_for_condition
label_desc: Use image node_id 2 for calling a global function with example usage: add_default_labels(node_info, labels) and returns: labels