/**
 * Defines a mechanism for measuring elapsed time.
 */
export declare class Stopwatch {
    private startTime;
    private endTime;
    /**
     * Gets a value indicating whether the Stopwatch is running.
     */
    isRunning: boolean;
    /**
     * Gets the total elapsed time measured by the current instance, in milliseconds, once stopped.
     */
    elapsedMilliseconds(): number;
    /**
     * Starts measuring elapsed time for an interval.
     */
    start(): void;
    /**
     * Stops measuring elapsed time for an interval.
     */
    stop(): void;
    /**
     * Stops time interval measurement and resets the elapsed time to zero.
     */
    reset(): void;
    /**
     * Stops time interval measurement, resets the elapsed time to zero, and starts measuring elapsed time.
     */
    restart(): void;
    /**
     * Initializes a new Stopwatch instance, sets the elapsed time property to zero, and starts measuring elapsed time.
     */
    static startNew(): Stopwatch;
}