import type { PerfServerMetricSample } from "./artifact.ts"; export interface PerfServerSampler {  readonly start: (input: { readonly pid: number }) => Promise<void>;  readonly stop: () => Promise<ReadonlyArray<PerfServerMetricSample> | null>;} export class NoopServerSampler implements PerfServerSampler {  async start(_input: { readonly pid: number }): Promise<void> {}   async stop(): Promise<null> {    return null;  }}