code: def clear_session_cookies(self):
          
          self._cookies_lock.acquire()
          try:
              for cookie in self:
                  if cookie.discard:
                      self.clear(cookie.domain, cookie.path, cookie.name)
          finally:
              self._cookies_lock.release()
docs: Discard all session cookies.
  
          Note that the .save() method won't save session cookies anyway, unless
          you ask otherwise by passing a true ignore_discard argument.