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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def batch_write_spans( self, name, spans, retry=google.api_core.gapic_v1.method.DEFAULT, timeout=google.api_core.gapic_v1.method.DEFAULT, metadata=None, ):
 """ Sends new spans to new or existing traces. You cannot update existing spans. Example: Args: name (str):
 Required. The name of the project where the spans belong. The format is ``projects/[PROJECT_ID]``. spans (list[Union[dict, ~google.cloud.trace_v2.types.Span]]):
 A list of new spans. The span names must not match existing spans, or the results are undefined. If a dict is provided, it must be of the same form as the protobuf message :class:`~google.cloud.trace_v2.types.Span` retry (Optional[google.api_core.retry.Retry]):
 A retry object used to retry requests. If ``None`` is specified, requests will not be retried. timeout (Optional[float]):
 The amount of time, in seconds, to wait for the request to complete. Note that if ``retry`` is specified, the timeout applies to each individual attempt. metadata (Optional[Sequence[Tuple[str, str]]]):
 Additional metadata that is provided to the method. Raises: google.api_core.exceptions.GoogleAPICallError: If the request failed for any reason. google.api_core.exceptions.RetryError: If the request failed due to a retryable error and retry attempts failed. ValueError: If the parameters are invalid. """

        # Wrap the transport method to add retry and timeout logic.
        if "batch_write_spans" not in self._inner_api_calls:
            self._inner_api_calls[
                "batch_write_spans"
            ] = google.api_core.gapic_v1.method.wrap_method(
                self.transport.batch_write_spans,
                default_retry=self._method_configs["BatchWriteSpans"].retry,
                default_timeout=self._method_configs["BatchWriteSpans"].timeout,
                client_info=self._client_info,
            )

        request = tracing_pb2.BatchWriteSpansRequest(name=name, spans=spans)
        if metadata is None:
            metadata = []
        metadata = list(metadata)
        try:
            routing_header = [("name", name)]
        except AttributeError:
            pass
        else:
            routing_metadata = google.api_core.gapic_v1.routing_header.to_grpc_metadata(
                routing_header
            )
            metadata.append(routing_metadata)

        self._inner_api_calls["batch_write_spans"](
            request, retry=retry, timeout=timeout, metadata=metadata
        )