import { Metric, Registry } from 'prom-client';
import { IMetricRegistry } from './registry.interface';
export declare class GenericMetric implements IMetricRegistry<Registry> {
    readonly register: Registry;
    constructor(labels?: {
        [key: string]: string;
    });
    metrics(): Promise<string>;
    get contentType(): "text/plain; version=0.0.4; charset=utf-8";
    addMetric(metric: Metric<any>): void;
    protected collectCustomMetrics(): void;
    collect(): (req: any, res: any, next: any) => void | Promise<void>;
}