function _updateMergely(sRawURLFrom, sRawURLTo){
            // lhs = from
            $.get(sRawURLFrom).done(function(sData){
                htElement.welMergely.mergely("lhs", sData);
                htElement.welMergely.mergely("resize");
                htElement.welMergely.mergely("update");
            });

            // rhs = to
            $.get(sRawURLTo).done(function(sData){
                htElement.welMergely.mergely("rhs", sData);
                htElement.welMergely.mergely("resize");
                htElement.welMergely.mergely("update");
            });
        }
@param {String} sRawURLFrom
@param {String} sRawURLTo