如何使用jquery验证插件验证select2元素？

Question

我使用select2 3.5.2和jquery验证1.13.1。我可以使用验证插件添加错误类到select2元素＆＃34;突出显示＆＃34;方法但是当我选择一个值时，我无法删除该错误类。我该如何解决这个问题？

HTML

<form id="test" class="frm">
    <div>
        <input type="text" name="name" />
    </div>
    <div>
        <label for="singleselect"></label>
        <select class="sl" id="singleselect" name="singleselect">
            <option></option>
            <option value="val1">Val-1</option>
            <option value="val2">Val-2</option>
        </select>
    </div>

    <div>
        <label for="multipleselect"></label>
        <select class="sl" id="multipleselect" name="multipleselect" multiple="multiple">
            <option></option>
            <option value="val1">Val-1</option>
            <option value="val2">Val-2</option>
        </select>
    </div>

    <button class="btn">Submit</button>
</form>

JS

$(document).ready(function () {

    $('.sl').select2({
        placeholder:'Select'   
    })

    $.validator.setDefaults({
        ignore: []
    });

    $('#test').validate({
        errorElement: 'span',
        errorClass: 'error',
        rules: {
            singleselect:'required',
            multipleselect:'required',
            name:'required'
        },

    highlight: function (element, errorClass, validClass) {

        var elem = $(element);

        elem.addClass(errorClass);

    },
    unhighlight: function (element, errorClass, validClass) {
        var elem = $(element);

            if(elem.hasClass('sl')) {
                elem.siblings('.sl').find('.select2-choice').removeClass(errorClass);
            } else {
                elem.removeClass(errorClass);
            }
        }
    });

});

https://jsfiddle.net/8Lyfa3k2/6/