How to use the josepy.JWS function in josepy

class Signature(jose.Signature):
    """ACME-specific Signature. Uses ACME-specific Header for customer fields."""
    __slots__ = jose.Signature._orig_slots  # pylint: disable=no-member

    # TODO: decoder/encoder should accept cls? Otherwise, subclassing
    # JSONObjectWithFields is tricky...
    header_cls = Header
    header = jose.Field(
        'header', omitempty=True, default=header_cls(),
        decoder=header_cls.from_json)

    # TODO: decoder should check that nonce is in the protected header


class JWS(jose.JWS):
    """ACME-specific JWS. Includes none, url, and kid in protected header."""
    signature_cls = Signature
    __slots__ = jose.JWS._orig_slots  # pylint: disable=no-member

    @classmethod
    # pylint: disable=arguments-differ
    def sign(cls, payload, key, alg, nonce, url=None, kid=None):
        # Per ACME spec, jwk and kid are mutually exclusive, so only include a
        # jwk field if kid is not provided.
        include_jwk = kid is None
        return super(JWS, cls).sign(payload, key=key, alg=alg,
                                    protect=frozenset(['nonce', 'url', 'kid', 'jwk', 'alg']),
                                    nonce=nonce, url=url, kid=kid,
                                    include_jwk=include_jwk)

:param unicode name: Domain name being validated.

        """
        return "{0}.{1}".format(self.LABEL, name)


@ChallengeResponse.register
class DNSResponse(ChallengeResponse):
    """ACME "dns" challenge response.

    :param JWS validation:

    """
    typ = "dns"

    validation = jose.Field("validation", decoder=jose.JWS.from_json)

    def check_validation(self, chall, account_public_key):
        """Check validation.

        :param challenges.DNS chall:
        :param JWK account_public_key:

        :rtype: bool

        """
        return chall.check_validation(self.validation, account_public_key)

__slots__ = jose.Signature._orig_slots  # pylint: disable=no-member

    # TODO: decoder/encoder should accept cls? Otherwise, subclassing
    # JSONObjectWithFields is tricky...
    header_cls = Header
    header = jose.Field(
        'header', omitempty=True, default=header_cls(),
        decoder=header_cls.from_json)

    # TODO: decoder should check that nonce is in the protected header


class JWS(jose.JWS):
    """ACME-specific JWS. Includes none, url, and kid in protected header."""
    signature_cls = Signature
    __slots__ = jose.JWS._orig_slots  # pylint: disable=no-member

    @classmethod
    # pylint: disable=arguments-differ
    def sign(cls, payload, key, alg, nonce, url=None, kid=None):
        # Per ACME spec, jwk and kid are mutually exclusive, so only include a
        # jwk field if kid is not provided.
        include_jwk = kid is None
        return super(JWS, cls).sign(payload, key=key, alg=alg,
                                    protect=frozenset(['nonce', 'url', 'kid', 'jwk', 'alg']),
                                    nonce=nonce, url=url, kid=kid,
                                    include_jwk=include_jwk)