code: def no_auth_environ():
      with EnvironmentVarGuard() as guard:
          # Temporarily unset credential environment variables
          guard.unset("DHUS_USER")
          guard.unset("DHUS_PASSWORD")
          yield
  
imports: import json
  import os
  import re
  import glob
  import shutil
  from contextlib import contextmanager
  from functools import partialmethod
  import pytest
  import requests_mock
  from click.testing import CliRunner
  from sentinelsat import SentinelAPI, InvalidChecksumError
  from sentinelsat.scripts.cli import cli
label_desc: Use image node_id 2 for calling a global function with example usage: no_auth_environ() without return types