group label="Group 1">
          <option value="1">January</option>
          <option value="2">February</option>
          <option value="3">March</option>
          <option data-divider="true"></option>
          <option value="4">April</option>
          <option value="5">May</option>
          <option value="6">June</option>
        </optgroup>
        <option data-divider="true"></option>
        <optgroup label="Group 2">
          <option value="7">July</option>
          <option value="8">August</op