How to use the acme.client.Client function in acme

def test_refresh_registration_for_unknown_key():
    m = M('''[account]
        dir = tests/support/valid
        acme-server = http://127.0.0.1:4000/directory
        [mgmt]''')
    m.load_private_key()
    assert type(m.key) is acme.jose.JWKRSA
    m.init_client()
    assert type(m.client) is acme.client.Client
    with pytest.raises(exceptions.AccountError) as e:
        m.refresh_registration()
    assert 'Key is not yet registered' in str(e)

def make_client(email=None):
    """Build an acme.Client and register a new account with a random key."""
    key = josepy.JWKRSA(key=rsa.generate_private_key(65537, 2048, default_backend()))

    net = acme_client.ClientNetwork(key, user_agent="Boulder integration tester")

    client = acme_client.Client(DIRECTORY, key=key, net=net)
    account = client.register(messages.NewRegistration.from_data(email=email))
    client.agree_to_tos(account)
    client.account = account
    return client

s3_client = boto3.client('s3', config=Config(signature_version='s3v4', region_name=s3_region))

    conf = load_config(s3_client, s3_bucket, letslambda_config)
    if conf == None:
        LOG.critical("Cannot load letslambda configuration. Exiting.")
        exit(1)

    conf['region'] = os.environ['AWS_DEFAULT_REGION']
    conf['s3_client'] = s3_client
    conf['s3_bucket'] = s3_bucket
    conf['letslambda_config'] = letslambda_config
    conf['kms_key'] = kms_key

    account_key = load_letsencrypt_account_key(conf)

    acme_client = client.Client(conf['directory'], account_key)
    for domain in conf['domains']:
        if 'r53_zone' not in domain.keys():
            LOG.error("Missing parameter 'r53_zone' for domain '{0}'. Skipping domain.".format(domain['name']))
            continue

        if 'kmsKeyArn' not in domain.keys():
            domain['kmsKeyArn'] = conf['kms_key']

        if 'reuse_key' not in domain.keys():
            domain['reuse_key'] = True

        if 'elb_port' not in domain.keys():
            domain['elb_port'] = 443

        if 'elb_region' not in domain.keys():
            domain['elb_region'] = conf['region']

def register_new_account(conf, key):
    """
    Attempt to create a new account on the ACME server
    with the key. No problem if it fails because this
    kye is already used.
    """
    LOG.info("Registering with ACME server with the new account key")
    newReg = messages.NewRegistration(contact=tuple(conf['info']), key=key.public_key())
    acme_client = client.Client(conf['directory'], key)
    registration_resource = acme_client.register(newReg)
    LOG.info("Agreeing on the TOS on your behalf")
    acme_client.agree_to_tos(registration_resource)

def acme_from_config_key(config, key):
    "Wrangle ACME client construction"
    # TODO: Allow for other alg types besides RS256
    net = acme_client.ClientNetwork(key, verify_ssl=(not config.no_verify_ssl),
                                    user_agent=_determine_user_agent(config))
    return acme_client.Client(config.server, key=key, net=net)

def acme_from_config_key(config, key):
    "Wrangle ACME client construction"
    # TODO: Allow for other alg types besides RS256
    net = acme_client.ClientNetwork(key, verify_ssl=(not config.no_verify_ssl),
                                    user_agent=determine_user_agent(config))
    return acme_client.Client(config.server, key=key, net=net)

def __init__(self, installer, config, no_confirm=False):
        # XXX
        self.acme = acme_client.Client(directory=None, key=None, alg=None)

        self.installer = installer
        self.config = config
        self.no_confirm = no_confirm

        le_util.make_or_verify_dir(config.cert_key_backup, 0o700, os.geteuid())

        # TODO: Find a better solution for this...
        self.list_path = os.path.join(config.cert_key_backup, "LIST")
        # Make sure that the file is available for use for rest of class
        open(self.list_path, "a").close()