public function __invoke(OutputBuffer $out)
{
$out->write('<!DOCTYPE ');
$out->writeEscaped($this->element);
if ($this->hasAttribute('public')) {
$out->write(' PUBLIC "')->writeEscaped($this->public)->write('"');
}
if ($this->hasAttribute('system')) {
$out->write(' SYSTEM "')->writeEscaped($this->system)->write('"');
}
$out->write(">\n");
}
