code: public static function form($data = [])
      {
          $data = array_merge(self::$default_form, $data);
          
          $html = '<div class="am-g am-margin-top-sm">';
          $html .= '<div class="am-u-sm-' . $data['l_sm_num'] . ' am-u-md-' . $data['l_md_num'] . ' am-text-right">' . $data['title'] . '</div>';
          $html .= '<div class="am-u-sm-' . $data['r_sm_num'] . ' am-u-md-' . $data['r_md_num'] . ' am-u-end">';
          $html .= '<select name="' . $data['name'] . '" data-am-selected="{btnSize: \'sm\'}">';
          foreach ($data['list'] as $vo) {
              if ($data['value'] === $vo['value']) {
                  $html .= '<option selected value="' . $vo['value'] . '">' . $vo['name'] . '</option>';
              } else {
                  $html .= '<option value="' . $vo['value'] . '">' . $vo['name'] . '</option>';
              }
          }
          $html .= '</select>';
          $html .= '</div>';
          $html .= '</div>';
          
          return $html;
      }
docs: form
  
  @param array $data
  @return string