export declare function hasTimer(label: string): number | null;
export declare function startTimer(label?: string): void;
export declare function endTimer(label?: string, clear?: boolean): number;
/**
 * Optimally format milliseconds
 *
 * @example `1h 2m 3s`
 * @example `5m 18s`
 * @example `40s`
 * @param duration
 */
export declare function formatMilliseconds(duration: number): string;