code: def get_signing_key(self, key_type="", owner="", kid=None, **kwargs):
          
          return self.get("sig", key_type, owner, kid, **kwargs)
docs: Shortcut to use for signing keys only.
  
          :param key_type: Type of key (rsa, ec, oct, ..)
          :param owner: Who is the owner of the keys, "" == me (default)
          :param kid: A Key Identifier
          :param kwargs: Extra key word arguments
          :return: A possibly empty list of keys