code: def set_temp_url_key(self, key=None):
          
          if key is None:
              key = uuid.uuid4().hex
          meta = {"Temp-Url-Key": key}
          self.set_account_metadata(meta)
          self._cached_temp_url_key = key
docs: Sets the key for the Temporary URL for the account. It should be a key
          that is secret to the owner.
  
          If no key is provided, a UUID value will be generated and used. It can
          later be obtained by calling get_temp_url_key().