code: function(sel) {
        if (!this.length) {
          return this;
        }
        var matched = [],
      	 		el = this[0];
  
      	while (el = el.nextElementSibling) {
      		sel ?
      			(u(el).is(sel) && matched.push(el)) :
      			matched.push(el);
      	}
      	return u(matched);
      }
docs: nextAll method
  get all next element siblings
  @param  {string} [sel] - selector to filter siblings
  @return {object}         sibling elements