export type TSupportedMetricStoreValues = string | number | boolean;
export declare class MetricStore {
    private static $instance;
    private $data;
    private constructor();
    static getInstance(): MetricStore;
    purge(): void;
    set(key: string, value: TSupportedMetricStoreValues): void;
    get(key: string): TSupportedMetricStoreValues | null;
    increment(key: string): void;
    decrement(key: string): void;
}