declare module "fps-meter/fps-native" {

    /**
     * An utility class used to measure frames per second.
     */
    export class FPSCallback {

        /**
         * Initializes a new instance of FPSCallback class.
         */
        constructor(onFrame: (currentTimeMillis: number) => void);

        /**
         * Starts the frame per seconds measurement.
         */
        start(): void;

        /**
         * Stops the frame per seconds measurement.
         */
        stop(): void;

        /**
         * Gets if the current instance of FPSCallback is running.
         */
        running: boolean;
    }
}