code: def _clear_namespace():
      
      ok_names = set(default_backend.__dict__)
      ok_names.update(['gl2', 'glplus'])  # don't remove the module
      NS = globals()
      for name in list(NS.keys()):
          if name.lower().startswith('gl'):
              if name not in ok_names:
                  del NS[name]
docs: Clear names that are not part of the strict ES API