import { Elder } from '../core/Elder.js';
import Page from './Page.js';
/**
 * A little helper around perf_hooks.
 * Returns an object with a start and end function.
 *
 * This allows you to pass in a page.perf.start('name') and then page.perf.end('name') and the result is stored in a timings array.
 *
 */
export declare type PerfTiming = {
    name: string;
    duration: number;
};
export declare type PerfTimings = PerfTiming[];
export declare type PerfPayload = {
    start: (label: string) => void;
    end: (label: string) => void;
};
export declare type Perf = PerfPayload & {
    timings: PerfTimings;
    stop: () => void;
    prefix: (label: string) => PerfPayload;
    reset: () => void;
};
declare function perf(page: Page | Elder, force?: boolean): void;
export default perf;
export declare const displayPerfTimings: (timings: PerfTimings) => void;