stopEmbeddedContent( element, options = {} ) {

		options = extend( {
			// Defaults
			unloadIframes: true
		}, options );

		if( element && element.parentNode ) {
			// HTML5 media elements
			queryAll( element, 'video, audio' ).forEach( el => {
				if( !el.hasAttribute( 'data-ignore' ) && typeof el.pause === 'function' ) {
					el.setAttribute('data-paused-by-reveal', '');
					el.pause();
				}
			} );

			// Generic postMessage API for non-lazy loaded iframes
			queryAll( element, 'iframe' ).forEach( el => {
				if( el.contentWindow ) el.contentWindow.postMessage( 'slide:stop', '*' );
				el.removeEventListener( 'load', this.startEmbeddedIframe );
			});

			// YouTube postMessage API
			queryAll( element, 'iframe[src*="youtube.com/embed/"]' ).forEach( el => {
				if( !el.hasAttribute( 'data-ignore' ) && el.contentWindow && typeof el.contentWindow.postMessage === 'function' ) {
					el.contentWindow.postMessage( '{"event":"command","func":"pauseVideo","args":""}', '*' );
				}
			});

			// Vimeo postMessage API
			queryAll( element, 'iframe[src*="player.vimeo.com/"]' ).forEach( el => {
				if( !el.hasAttribute( 'data-ignore' ) && el.contentWindow && typeof el.contentWindow.postMessage === 'function' ) {
					el.contentWindow.postMessage( '{"method":"pause"}', '*' );
				}
			});

			if( options.unloadIframes === true ) {
				// Unload lazy-loaded iframes
				queryAll( element, 'iframe[data-src]' ).forEach( el => {
					// Only removing the src doesn't actually unload the frame
					// in all browsers (Firefox) so we set it to blank first
					el.setAttribute( 'src', 'about:blank' );
					el.removeAttribute( 'src' );
				} );
			}
		}

	}
Stop playback of any embedded content inside of
the targeted slide.

@param {HTMLElement} element