pub(super) fn observe_latency(
        &self,
        meta: &MethodMetadata,
        raw_params: &ObservedRpcParams<'_>,
    ) {
        static FILTER: ReportFilter = report_filter!(Duration::from_secs(1));
        const MIN_REPORTED_LATENCY: Duration = Duration::from_secs(5);

        let latency = meta.started_at.elapsed();
        self.web3_call[&MethodLabels::from(meta)].observe(latency);
        if let Some(block_diff) = meta.block_diff {
            self.web3_call_block_diff[&meta.name].observe(block_diff.into());
        }
        if latency >= MIN_REPORTED_LATENCY && FILTER.should_report() {
            tracing::info!("Long call to `{}`{raw_params}: {latency:?}", meta.name);
        }
    }
Observes latency of a finished RPC call.
core/node/api_server/src/web3/metrics.rs