availableRoutes() {

		let currentSlide = this.Reveal.getCurrentSlide();
		if( currentSlide && this.Reveal.getConfig().fragments ) {
			let fragments = currentSlide.querySelectorAll( '.fragment:not(.disabled)' );
			let hiddenFragments = currentSlide.querySelectorAll( '.fragment:not(.disabled):not(.visible)' );

			return {
				prev: fragments.length - hiddenFragments.length > 0,
				next: !!hiddenFragments.length
			};
		}
		else {
			return { prev: false, next: false };
		}

	}
Returns an object describing the available fragment
directions.

@return {{prev: boolean, next: boolean}}