public function cachedTranslation($key, $locale)
{
list($group, $transKey) = self::groupKeyList($key);
$cacheKey = $this->cacheKey($transKey, $locale);
$value = $group && array_key_exists($group, $this->cache()) && array_key_exists($cacheKey, $this->cache[$group]) ? $this->cache[$group][$cacheKey] : null;
return $value;
}