slugger = $slugger ?: new AsciiSlugger(); } public function getFilters() { return [ new TwigFilter('u', [$this, 'createUnicodeString']), new TwigFilter('slug', [$this, 'createSlug']), ]; } public function createUnicodeString(?string $text): UnicodeString { return new UnicodeString($text ?? ''); } public function createSlug(string $string, string $separator = '-', ?string $locale = null): AbstractUnicodeString { return $this->slugger->slug($string, $separator, $locale); } }