slidePlayerPause(slide) {
        if (_.isNode(slide)) {
            let node = slide.querySelector('.gvideo-wrapper');
            if (node) {
                slide = node.getAttribute('data-index');
            }
        }
        const player = this.getSlidePlayerInstance(slide);
        if (player && player.playing) {
            player.pause();
        }
    }
Stop player at specified index

@param slide node or index
@return void