var loadContent = function(){

    $.ajax({
         url: '/url',
         method: 'GET'
    }).success(function (html) {

         $('.content-wrapper').replaceWith(html);

    })

    //this is how simple returned html looks like
    //<div class="content-wrapper"><ul"><li>test</li></ul></div>

};

var testAjaxGeneratedHtml = function() {
    loadContent();
    $('.content-wrapper ul li').addClass('test');
}