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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 list_traces( self, project_id, view=None, page_size=None, start_time=None, end_time=None, filter_=None, order_by=None, retry=google.api_core.gapic_v1.method.DEFAULT, timeout=google.api_core.gapic_v1.method.DEFAULT, metadata=None, ):
 """ Returns of a list of traces that match the specified filter conditions. Example: Args: project_id (str):
 ID of the Cloud project where the trace data is stored. view (~google.cloud.trace_v1.types.ViewType):
 Type of data returned for traces in the list. Optional. Default is ``MINIMAL``. page_size (int):
 The maximum number of resources contained in the underlying API response. If page streaming is performed per- resource, this parameter does not affect the return value. If page streaming is performed per-page, this determines the maximum number of resources in a page. start_time (Union[dict, ~google.cloud.trace_v1.types.Timestamp]):
 Start of the time interval (inclusive) during which the trace data was collected from the application. If a dict is provided, it must be of the same form as the protobuf message :class:`~google.cloud.trace_v1.types.Timestamp` end_time (Union[dict, ~google.cloud.trace_v1.types.Timestamp]):
 End of the time interval (inclusive) during which the trace data was collected from the application. If a dict is provided, it must be of the same form as the protobuf message :class:`~google.cloud.trace_v1.types.Timestamp` filter_ (str):
 An optional filter against labels for the request. By default, searches use prefix matching. To specify exact match, prepend a plus symbol (``+``) to the search term. Multiple terms are ANDed. Syntax: - ``root:NAME_PREFIX`` or ``NAME_PREFIX``: Return traces where any root span starts with ``NAME_PREFIX``. - ``+root:NAME`` or ``+NAME``: Return traces where any root span's name is exactly ``NAME``. - ``span:NAME_PREFIX``: Return traces where any span starts with ``NAME_PREFIX``. - ``+span:NAME``: Return traces where any span's name is exactly ``NAME``. - ``latency:DURATION``: Return traces whose overall latency is greater or equal to than ``DURATION``. Accepted units are nanoseconds (``ns``), milliseconds (``ms``), and seconds (``s``). Default is ``ms``. For example, ``latency:24ms`` returns traces whose overall latency is greater than or equal to 24 milliseconds. - ``label:LABEL_KEY``: Return all traces containing the specified label key (exact match, case-sensitive) regardless of the key:value pair's value (including empty values). - ``LABEL_KEY:VALUE_PREFIX``: Return all traces containing the specified label key (exact match, case-sensitive) whose value starts with ``VALUE_PREFIX``. Both a key and a value must be specified. - ``+LABEL_KEY:VALUE``: Return all traces containing a key:value pair exactly matching the specified text. Both a key and a value must be specified. - ``method:VALUE``: Equivalent to ``/http/method:VALUE``. - ``url:VALUE``: Equivalent to ``/http/url:VALUE``. order_by (str):
 Field used to sort the returned traces. Optional. Can be one of the following: - ``trace_id`` - ``name`` (``name`` field of root span in the trace) - ``duration`` (difference between ``end_time`` and ``start_time`` fields of the root span) - ``start`` (``start_time`` field of the root span) Descending order can be specified by appending ``desc`` to the sort field (for example, ``name desc``). Only one sort field is permitted. 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. Returns: A :class:`~google.gax.PageIterator` instance. By default, this is an iterable of :class:`~google.cloud.trace_v1.types.Trace` instances. This object can also be configured to iterate over the pages of the response through the `options` parameter. 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 "list_traces" not in self._inner_api_calls:
            self._inner_api_calls[
                "list_traces"
            ] = google.api_core.gapic_v1.method.wrap_method(
                self.transport.list_traces,
                default_retry=self._method_configs["ListTraces"].retry,
                default_timeout=self._method_configs["ListTraces"].timeout,
                client_info=self._client_info,
            )

        request = trace_pb2.ListTracesRequest(
            project_id=project_id,
            view=view,
            page_size=page_size,
            start_time=start_time,
            end_time=end_time,
            filter=filter_,
            order_by=order_by,
        )
        if metadata is None:
            metadata = []
        metadata = list(metadata)
        try:
            routing_header = [("project_id", project_id)]
        except AttributeError:
            pass
        else:
            routing_metadata = google.api_core.gapic_v1.routing_header.to_grpc_metadata(
                routing_header
            )
            metadata.append(routing_metadata)

        iterator = google.api_core.page_iterator.GRPCIterator(
            client=None,
            method=functools.partial(
                self._inner_api_calls["list_traces"],
                retry=retry,
                timeout=timeout,
                metadata=metadata,
            ),
            request=request,
            items_field="traces",
            request_token_field="page_token",
            response_token_field="next_page_token",
        )
        return iterator