code: public function renderItems()
      {
          $caption = $this->renderCaption();
          $columnGroup = $this->renderColumnGroup();
          $tableHeader = $this->showHeader ? $this->renderTableHeader() : false;
          $tableBody = $this->renderTableBody();
  
          $tableFooter = false;
          $tableFooterAfterBody = false;
          
          if ($this->showFooter) {
              if ($this->placeFooterAfterBody) {
                  $tableFooterAfterBody = $this->renderTableFooter();
              } else {
                  $tableFooter = $this->renderTableFooter();
              }
          }
  
          $content = array_filter([
              $caption,
              $columnGroup,
              $tableHeader,
              $tableFooter,
              $tableBody,
              $tableFooterAfterBody,
          ]);
  
          return Html::tag('table', implode("\n", $content), $this->tableOptions);
      }
docs: Renders the data models for the grid view.
  @return string the HTML code of table