protected function renderHeaderContent($writer)
{
$url = $this->getNavigateUrl();
if (($caption = $this->getCaption()) === '') {
$caption = ' ';
}
if ($url != '') {
$writer->write("<a href=\"{$url}\">");
}
$writer->write("{$caption}");
if ($url != '') {
$writer->write("</a>");
}
}