code: def set_cookie(  # type: ignore
              self,
              key: str,
              value: AnyStr='',
              max_age: Optional[Union[int, timedelta]]=None,
              expires: Optional[datetime]=None,
              path: str='/',
              domain: Optional[str]=None,
              secure: bool=False,
              httponly: bool=False,
      ) -> None:
          
          if isinstance(value, bytes):
              value = value.decode()  # type: ignore
          cookie = create_cookie(key, value, max_age, expires, path, domain, secure, httponly)  # type: ignore  # noqa: E501
          self.headers.add('Set-Cookie', cookie.output(header=''))
docs: Set a cookie in the response headers.
  
          The arguments are the standard cookie morsels and this is a
          wrapper around the stdlib SimpleCookie code.