code: public function tf(string $key, array $args = null, N2nLocale ...$n2nLocales): string {
  		foreach ($this->dbtextCollections as $dbtextCollection) {
  			if ($dbtextCollection->has($key)) {
  				return $dbtextCollection->tf($key, $args, ...$this->n2nLocales);
  			}
  		}
  
  		if (reset($this->dbtextCollections)) {
  			return reset($this->dbtextCollections)->t($key);
  		}
  		
  		return $key;
  	}
docs: Finds most fitting {@see TextT} by locales provided and returns modified {@see TextT::$str}.
  {@see TextT::$str} args are replaced by the printf method.
  
  @param string $key
  @param array $args
  @param N2nLocale[] ...$n2nLocales
  @return string