Code to write to Feature Store

@beam.typehints.with_input_types(Tuple[User, List[str]])
class WriteFeatureRPC(beam.DoFn):
    def __init__(
        self,
        api_endpoint,
        project_id,
        location,
        featurestore_id,
        entity_type_id,
        feature_name,
    ):
        self.write_time_dist = Metrics.distribution("writer", "write_time")
        self.serialize_time_dist = Metrics.distribution("writer", "serialize_time")
        self.client_setup_time_dist = Metrics.distribution(
            "writer", "client_setup_time"
        )
        self.project_id = project_id
        self.location = location
        self.featurestore_id = featurestore_id
        self.entity_type_id = entity_type_id
        self.api_endpoint = api_endpoint
        self.feature_name = feature_name

    def setup(self):
        start_time = time.time()
        self.client = self._create_client()
        self.client_setup_time_dist.update(int((time.time() - start_time) * 1000))
        self.buffer = []

    def process(self, element):
        start_time = time.time()
        entity_id = element[0].id + "_" + element[0].market
        feature_values = {
            self.feature_name: featurestore_online_service_pb2.FeatureValue(
                string_array_value=types_pb2.StringArray(values=element[1])
            ),
            "market": featurestore_online_service_pb2.FeatureValue(
                string_value=element[0].market
            ),
        }
        payload = featurestore_online_service_pb2.WriteFeatureValuesPayload(
            entity_id=entity_id, feature_values=feature_values
        )
        self.serialize_time_dist.update(int((time.time() - start_time) * 1000))
        self.buffer.append(payload)

    def _create_client(self):
        return FeaturestoreOnlineServingServiceClient(
            client_options={"api_endpoint": self.api_endpoint}
        )

    def finish_bundle(self):
        if not self.client:
            self.client = self._create_client()
        start_time = time.time()
        entity_type_path = self.client.entity_type_path(
            self.project_id, self.location, self.featurestore_id, self.entity_type_id
        )
        self.client.write_feature_values(
            entity_type=entity_type_path,
            payloads=self.buffer,
        )
        self.write_time_dist.update(int((time.time() - start_time) * 1000))
        self.buffer.clear()