code: public function renderSummary(SummaryFormInterface $form)
      {
          $form->prepare();
          $baseFieldset = $form->getBaseFieldset();
          if (!isset($baseFieldset)) {
              throw new \InvalidArgumentException('For the Form ' . get_class($form) . ' there is no Basefieldset');
          }
  
          $dataAttributesMarkup = '';
          
          foreach ($form->getAttributes() as $dataKey => $dataValue) {
              if (preg_match('/^data-/', $dataKey)) {
                  $dataAttributesMarkup .= sprintf(' %s="%s"', $dataKey, $dataValue);
              }
          }
          
          $markup = '<div class="panel panel-default" style="min-height: 100px;"' . $dataAttributesMarkup . '>
                      <div class="panel-body"><div class="sf-controls">%s</div>%s</div></div>';
  
          $view = $this->getView();
          $buttonMarkup = false === $form->getOption('editable')
                        ? ''
                        : '<button type="button" class="btn btn-default btn-xs sf-edit">'
                          . '<span class="yk-icon yk-icon-edit"></span> '
                          . $view->translate('Edit')
                          . '</button>';
          
          if (($controlButtons = $form->getOption('control_buttons')) !== null) {
              $buttonMarkup .= PHP_EOL . implode(PHP_EOL, array_map(function (array $buttonSpec) use ($view) {
                  return '<button type="button" class="btn btn-default btn-xs' . (isset($buttonSpec['class']) ? ' ' . $buttonSpec['class'] : '') . '">'
                      . (isset($buttonSpec['icon']) ? '<span class="yk-icon yk-icon-' . $buttonSpec['icon'] . '"></span> ' : '')
                      . $view->translate($buttonSpec['label'])
                      . '</button>';
              }, $controlButtons));
          }
  
          $elementMarkup = $this->renderSummaryElement($baseFieldset);
  
  
          return sprintf($markup, $buttonMarkup, $elementMarkup);
      }
docs: Only renders the summary representation of a summary form
  
  @param SummaryFormInterface $form
  @return string