src/Cache/RuntimeCache.php
public function getNotCachedAttributes($key, array $attributes = ['*'])
    {
        if (!$this->has($key)) {
            return $attributes;
        }
        $cachedAttributes = $this->cache[$key]['attributes'];
        return $cachedAttributes == ['*'] ? [] : array_diff($attributes, $cachedAttributes);
    }
public function getNotCachedAttributes($key, array $attributes = ['*'])
    {
        if (!$this->has($key)) {
            return $attributes;
        }
        $cachedAttributes = $this->cache[$key]['attributes'];
        return $cachedAttributes == ['*'] ? [] : array_diff($attributes, $cachedAttributes);
    }
Return the difference between given attributes and attributes which are already cached.

@param mixed $key
@param array $attributes
@return array