code: def delenv():
      """Delete options in the existing environment."""
      if not local._env:
          raise EnvError("No GDAL environment exists")
      else:
          local._env.clear_config_options()
          log.debug("Cleared existing %r options", local._env)
      local._env.stop()
      local._env = None
  
imports: from functools import wraps, total_ordering
  from inspect import getfullargspec
  import logging
  import os
  import re
  import threading
  import warnings
  import attr
  from rasterio._env import GDALEnv, get_gdal_config, set_gdal_config, GDALDataFinder, PROJDataFinder, set_proj_data_search_path
  from rasterio._version import gdal_version
  from rasterio.errors import EnvError, GDALVersionError, RasterioDeprecationWarning
  from rasterio.session import Session, DummySession
label_desc: Use image node_id 6 for calling a global function with example usage: delenv() without return types