def match_owner(self, url):
        """
        Finds the first entity, with keys in the key jar, with an
        identifier that matches the given URL. The match is a leading
        substring match.

        :param url: A URL
        :return: An issue entity ID that exists in the Key jar
        """
        for owner in self.issuer_keys.keys():
            if owner.startswith(url):
                return owner

        raise KeyError("No keys for '{}' in this keyjar".format(url))
def match_owner ( self , url ) : for owner in self . issuer_keys . keys ( ) : if owner . startswith ( url ) : return owner raise KeyError ( "No keys for '{}' in this keyjar" . format ( url ) )
Finds the first entity, with keys in the key jar, with an
        identifier that matches the given URL. The match is a leading
        substring match.

        :param url: A URL
        :return: An issue entity ID that exists in the Key jar