code: def get_secure_cookie_key_version(
          self, name: str, value: str = None
      ) -> Optional[int]:
          
          self.require_setting("cookie_secret", "secure cookies")
          if value is None:
              value = self.get_cookie(name)
          if value is None:
              return None
          return get_signature_key_version(value)
docs: Returns the signing key version of the secure cookie.
  
          The version is returned as int.