public function generate()
{
$title = $this->getTitle();
$description = $this->getDescription();
$keywords = $this->getKeywords();
$canonical = $this->getCanonical();
$html[] = "<title>{$title}</title>";
if (!empty($description)) {
$html[] = "<meta name='description' content='{$description}' />";
}
if (!empty($keywords)) {
$html[] = "<meta name='keywords' content='{$keywords}' />";
}
if (!empty($canonical)) {
$html[] = "<link rel='canonical' href='{$canonical}' />";
}
return implode(PHP_EOL, $html);
}