How to use the awscrt.auth.AwsCredentialsProvider.new_default_chain function in awscrt

def test_default_provider(self):
        # Use environment variable to force specific credentials file
        scoped_env = ScopedEnvironmentVariable('AWS_SHARED_CREDENTIALS_FILE', 'test/resources/credentials_test')

        event_loop_group = awscrt.io.EventLoopGroup()
        host_resolver = awscrt.io.DefaultHostResolver(event_loop_group)
        bootstrap = awscrt.io.ClientBootstrap(event_loop_group, host_resolver)
        provider = awscrt.auth.AwsCredentialsProvider.new_default_chain(bootstrap)

        future = provider.get_credentials()
        credentials = future.result(TIMEOUT)

        self.assertEqual('credentials_test_access_key_id', credentials.access_key_id)
        self.assertEqual('credentials_test_secret_access_key', credentials.secret_access_key)
        self.assertIsNone(credentials.session_token)

        del scoped_env

def test_websockets_default(self):
        config = Config.get()
        elg = EventLoopGroup()
        resolver = DefaultHostResolver(elg)
        bootstrap = ClientBootstrap(elg, resolver)
        cred_provider = AwsCredentialsProvider.new_default_chain(bootstrap)
        connection = awsiot_mqtt_connection_builder.websockets_with_default_aws_signing(
            region=config.region,
            credentials_provider=cred_provider,
            endpoint=config.endpoint,
            client_id=create_client_id(),
            client_bootstrap=bootstrap)
        self._test_connection(connection)

def test_websockets_proxy(self):
        config = Config.get()
        elg = EventLoopGroup()
        resolver = DefaultHostResolver(elg)
        bootstrap = ClientBootstrap(elg, resolver)
        cred_provider = AwsCredentialsProvider.new_default_chain(bootstrap)
        connection = awsiot_mqtt_connection_builder.websockets_with_default_aws_signing(
            credentials_provider=cred_provider,
            websocket_proxy_options=HttpProxyOptions(PROXY_HOST, PROXY_PORT),
            endpoint=config.endpoint,
            region=config.region,
            client_id=create_client_id(),
            client_bootstrap=bootstrap)
        self._test_connection(connection)

# Process input args
    args = parser.parse_args()
    thing_name = args.thing_name
    io.init_logging(getattr(io.LogLevel, args.verbosity), 'stderr')

    # Spin up resources
    event_loop_group = io.EventLoopGroup(1)
    host_resolver = io.DefaultHostResolver(event_loop_group)
    client_bootstrap = io.ClientBootstrap(event_loop_group, host_resolver)

    if args.use_websocket == True:
        proxy_options = None
        if (args.proxy_host):
            proxy_options = http.HttpProxyOptions(host_name=args.proxy_host, port=args.proxy_port)

        credentials_provider = auth.AwsCredentialsProvider.new_default_chain(client_bootstrap)
        mqtt_connection = mqtt_connection_builder.websockets_with_default_aws_signing(
            endpoint=args.endpoint,
            client_bootstrap=client_bootstrap,
            region=args.signing_region,
            credentials_provider=credentials_provider,
            websocket_proxy_options=proxy_options,
            ca_filepath=args.root_ca,
            client_id=args.client_id,
            clean_session=False,
            keep_alive_secs=6)

    else:
        mqtt_connection = mqtt_connection_builder.mtls_from_path(
            endpoint=args.endpoint,
            cert_filepath=args.cert,
            pri_key_filepath=args.key,

received_count += 1
    if received_count == args.count:
        received_all_event.set()

if __name__ == '__main__':
    # Spin up resources
    event_loop_group = io.EventLoopGroup(1)
    host_resolver = io.DefaultHostResolver(event_loop_group)
    client_bootstrap = io.ClientBootstrap(event_loop_group, host_resolver)

    if args.use_websocket == True:
        proxy_options = None
        if (args.proxy_host):
            proxy_options = http.HttpProxyOptions(host_name=args.proxy_host, port=args.proxy_port)

        credentials_provider = auth.AwsCredentialsProvider.new_default_chain(client_bootstrap)
        mqtt_connection = mqtt_connection_builder.websockets_with_default_aws_signing(
            endpoint=args.endpoint,
            client_bootstrap=client_bootstrap,
            region=args.signing_region,
            credentials_provider=credentials_provider,
            websocket_proxy_options=proxy_options,
            ca_filepath=args.root_ca,
            on_connection_interrupted=on_connection_interrupted,
            on_connection_resumed=on_connection_resumed,
            client_id=args.client_id,
            clean_session=False,
            keep_alive_secs=6)

    else:
        mqtt_connection = mqtt_connection_builder.mtls_from_path(
            endpoint=args.endpoint,

loopCount += 1
        print('Waiting... RegisterThingResponse: ' + json.dumps(registerThingResponse))
        time.sleep(1)

if __name__ == '__main__':
    # Spin up resources
    event_loop_group = io.EventLoopGroup(1)
    host_resolver = io.DefaultHostResolver(event_loop_group)
    client_bootstrap = io.ClientBootstrap(event_loop_group, host_resolver)

    if args.use_websocket == True:
        proxy_options = None
        if (args.proxy_host):
            proxy_options = http.HttpProxyOptions(host_name=args.proxy_host, port=args.proxy_port)

        credentials_provider = auth.AwsCredentialsProvider.new_default_chain(client_bootstrap)
        mqtt_connection = mqtt_connection_builder.websockets_with_default_aws_signing(
            endpoint=args.endpoint,
            client_bootstrap=client_bootstrap,
            region=args.signing_region,
            credentials_provider=credentials_provider,
            websocket_proxy_options=proxy_options,
            on_connection_interrupted=on_connection_interrupted,
            on_connection_resumed=on_connection_resumed,
            ca_filepath=args.root_ca,
            client_id=args.client_id,
            clean_session=False,
            keep_alive_secs=6)

    else:
        mqtt_connection = mqtt_connection_builder.mtls_from_path(
            endpoint=args.endpoint,

args = parser.parse_args()
    thing_name = args.thing_name
    shadow_property = args.shadow_property
    io.init_logging(getattr(io.LogLevel, args.verbosity), 'stderr')

    # Spin up resources
    event_loop_group = io.EventLoopGroup(1)
    host_resolver = io.DefaultHostResolver(event_loop_group)
    client_bootstrap = io.ClientBootstrap(event_loop_group, host_resolver)

    if args.use_websocket == True:
        proxy_options = None
        if (args.proxy_host):
            proxy_options = http.HttpProxyOptions(host_name=args.proxy_host, port=args.proxy_port)

        credentials_provider = auth.AwsCredentialsProvider.new_default_chain(client_bootstrap)
        mqtt_connection = mqtt_connection_builder.websockets_with_default_aws_signing(
            endpoint=args.endpoint,
            client_bootstrap=client_bootstrap,
            region=args.signing_region,
            credentials_provider=credentials_provider,
            websocket_proxy_options=proxy_options,
            ca_filepath=args.root_ca,
            client_id=args.client_id,
            clean_session=False,
            keep_alive_secs=6)

    else:
        mqtt_connection = mqtt_connection_builder.mtls_from_path(
            endpoint=args.endpoint,
            cert_filepath=args.cert,
            pri_key_filepath=args.key,