code: def get_current_usage():
      usage = shutil.disk_usage("/tmp")
      print(f"free: {usage.free} ")
      usage_percentage = 1.0 - 1.0 * usage.free / usage.total
      print(f"current usage: {usage_percentage}")
      return usage_percentage
  
file_path: ray/python/ray/tests/test_out_of_disk_space.py
imports: import os
  import platform
  import shutil
  import sys
  import tempfile
  import time
  from contextlib import contextmanager
  import numpy
  import pytest
  import ray
  from ray.util.state import list_cluster_events
label_desc: Use image node_id 2 for calling a global function with example usage: get_current_usage() and returns: usage_percentage