code: def test_set_env() -> None:
      with tools.set_env(BLUBLU=1):
          assert os.environ.get("BLUBLU", None) == "1"
      assert os.environ.get("BLUBLU", None) is None
  
file_path: nevergrad/nevergrad/common/test_tools.py
imports: import os
  import typing
  import numpy
  from .None import tools
  from .None import testing
label_desc: Use image node_id 6 for calling a global function with example usage: test_set_env() without return types