code: def install_middleware(middleware_name, lookup_names=None):
      
      if lookup_names is None:
          lookup_names = (middleware_name,)
      # default settings.MIDDLEWARE is None
      middleware_attr = 'MIDDLEWARE' if getattr(settings,
                                                'MIDDLEWARE',
                                                None) is not None \
          else 'MIDDLEWARE_CLASSES'
      # make sure to get an empty tuple when attr is None
      middleware = getattr(settings, middleware_attr, ()) or ()
      if set(lookup_names).isdisjoint(set(middleware)):
          setattr(settings,
                  middleware_attr,
                  type(middleware)((middleware_name,)) + middleware)
docs: Install specified middleware