src/Manager.php
public function cachedTranslation($namespace, $group, $transKey, $locale)
    {
        $group = self::fixGroup($group);
        $group = $namespace && $namespace !== '*' ? $namespace . '::' . $group : $group;

        $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 $value;
    }
public function cachedTranslation($namespace, $group, $transKey, $locale)
    {
        $group = self::fixGroup($group);
        $group = $namespace && $namespace !== '*' ? $namespace . '::' . $group : $group;

        $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;
    }
@param $namespace
@param $group
@param $transKey
@param $locale

@return string|null translation value