def get_scheme(cls, hashed_passord):
        """
            Return the scheme of ``hashed_passord`` or raise :attr:`BadHash`

            :param bytes hashed_passord: A hashed password
            :return: The scheme used by the hashed password
            :rtype: bytes
            :raises BadHash: if no valid scheme is found within ``hashed_passord``
        """
        if not hashed_passord[0] == b'{'[0] or b'}' not in hashed_passord:
            raise cls.BadHash("%r should start with the scheme enclosed with { }" % hashed_passord)
        scheme = hashed_passord.split(b'}', 1)[0]
        scheme = scheme.upper() + b"}"
        return scheme
Return the scheme of ``hashed_passord`` or raise :attr:`BadHash`

            :param bytes hashed_passord: A hashed password
            :return: The scheme used by the hashed password
            :rtype: bytes
            :raises BadHash: if no valid scheme is found within ``hashed_passord``