code: def test_is_local_rank_0(self) -> None:
      block = cflearn.SetDefaultsBlock()
      self.assertTrue(block.is_local_rank_0)
      os.environ["RANK"] = "0"
      os.environ["WORLD_SIZE"] = "2"
      os.environ["LOCAL_RANK"] = "0"
      self.assertTrue(block.is_local_rank_0)
      os.environ["LOCAL_RANK"] = "1"
      self.assertFalse(block.is_local_rank_0)
      os.environ["RANK"] = "1"
      os.environ["LOCAL_RANK"] = "0"
      self.assertTrue(block.is_local_rank_0)
      os.environ.pop("RANK")
      os.environ.pop("WORLD_SIZE")
      os.environ.pop("LOCAL_RANK")
  
file_path: carefree-learn/tests/test_pipeline.py
imports: import os
  import torch
  import cflearn
  import unittest
  import numpy
label_desc: Use image node_id 3 for calling the TestPipeline obj's underlying member method code with example usage: obj.test_is_local_rank_0() without return types