setFrameRate(id, frameRate) {
        const instance = animation.instances[id];

        if (instance) {
            if (frameRate > 0) {
                instance.frameRate = frameRate;
            } else {
                delete instance.frameRate;
            }
        }
    }
Set the frame rate to an animation.
@param {number} id - Animation ID to set
@param {number} frameRate - Frames per second of the animation. If set to 0 or
    not specified, the default value (browser's native fps) will be applied.