feat: Update timestamp handling in AggregatedLinkSample to use datetime object directly

                    ))

                    # Return a copy with updated timestamp

                    return AggregatedLinkSample(

                        timestamp=datetime.now(timezone.utc).isoformat(),

                        timestamp=datetime.now(timezone.utc),

                        bandwidth_utilization=self._last_valid_aggregation.bandwidth_utilization,

                        latency=self._last_valid_aggregation.latency,

                        related_service_ids=self._last_valid_aggregation.related_service_ids.copy()

                else:

                    MSG = '[aggregate] No samples available and no cached data, returning zeros'

                    LOGGER.warning(MSG)

                    return AggregatedLinkSample(timestamp=datetime.now(timezone.utc).isoformat())

                    return AggregatedLinkSample(timestamp=datetime.now(timezone.utc))

            agg = AggregatedLinkSample(timestamp=datetime.now(timezone.utc).isoformat())

            agg = AggregatedLinkSample(timestamp=datetime.now(timezone.utc))

            for link_key, sample in self._samples.items():

                network_id, link_id = link_key