How to use the baseplate.lib.metrics function in baseplate

def test_make_batch(self):
        transport = mock.Mock(spec=metrics.NullTransport)
        client = metrics.Client(transport, "namespace")
        batch = client.batch()

        self.assertIsInstance(batch, metrics.Batch)
        self.assertEqual(batch.namespace, b"namespace")

def setUp(self, mock_Session):
        self.session = mock_Session.return_value
        self.metrics_client = mock.MagicMock(autospec=metrics.Client)
        self.zipkin_api_url = "http://test.local/api/v2"
        self.publisher = trace_publisher.ZipkinPublisher(self.zipkin_api_url, self.metrics_client)

def setUp(self):
        transport = mock.Mock(spec=metrics.NullTransport)
        self.client = metrics.BaseClient(transport, "namespace")

def test_make_batch(self):
        transport = mock.Mock(spec=metrics.NullTransport)
        client = metrics.Client(transport, "namespace")
        batch = client.batch()

        self.assertIsInstance(batch, metrics.Batch)
        self.assertEqual(batch.namespace, b"namespace")

def test_make_counter(self):
        counter = self.client.counter("some_counter")
        self.assertIsInstance(counter, metrics.Counter)
        self.assertEqual(counter.name, b"namespace.some_counter")

        with self.assertRaises(UnicodeEncodeError):
            self.client.counter("☃")

def test_buffered_exception_is_caught(self):
        raw_transport = metrics.RawTransport(EXAMPLE_ENDPOINT)
        transport = metrics.BufferedTransport(raw_transport)
        transport.send(b"x" * 65536)

        with self.assertRaises(metrics.MessageTooBigTransportError):
            transport.flush()

def setUp(self, Session):
        self.config = config.ConfigNamespace()
        self.config.collector = config.ConfigNamespace()
        self.config.collector.hostname = "test.local"
        self.config.collector.version = 1
        self.config.key = config.ConfigNamespace()
        self.config.key.name = "TestKey"
        self.config.key.secret = b"hunter2"

        self.session = Session.return_value

        self.metrics_client = mock.MagicMock(autospec=metrics.Client)

        self.publisher = event_publisher.BatchPublisher(self.metrics_client, self.config)

def test_no_endpoint(self):
        client = metrics.make_client("namespace", None)
        self.assertIsInstance(client.transport, metrics.NullTransport)

def test_two_nodes(self):
        joined = metrics._metric_join(b"first", b"second")
        self.assertEqual(joined, b"first.second")

def __init__(self, app_config: Optional[config.RawConfig] = None) -> None:
        self.observers: List[BaseplateObserver] = []
        self._metrics_client: Optional[metrics.Client] = None
        self._context_config: Dict[str, Any] = {}
        self._app_config = app_config