in assets/js/slick.js [2945:2978]
Slick.prototype.updateArrows = function() {
var _ = this,
centerOffset;
centerOffset = Math.floor(_.options.slidesToShow / 2);
if ( _.options.arrows === true &&
_.slideCount > _.options.slidesToShow &&
!_.options.infinite ) {
_.$prevArrow.removeClass('slick-disabled').attr('aria-disabled', 'false');
_.$nextArrow.removeClass('slick-disabled').attr('aria-disabled', 'false');
if (_.currentSlide === 0) {
_.$prevArrow.addClass('slick-disabled').attr('aria-disabled', 'true');
_.$nextArrow.removeClass('slick-disabled').attr('aria-disabled', 'false');
} else if (_.currentSlide >= _.slideCount - _.options.slidesToShow && _.options.centerMode === false) {
_.$nextArrow.addClass('slick-disabled').attr('aria-disabled', 'true');
_.$prevArrow.removeClass('slick-disabled').attr('aria-disabled', 'false');
} else if (_.currentSlide >= _.slideCount - 1 && _.options.centerMode === true) {
_.$nextArrow.addClass('slick-disabled').attr('aria-disabled', 'true');
_.$prevArrow.removeClass('slick-disabled').attr('aria-disabled', 'false');
}
}
};