framework/caching/ApcCache.php
protected function getValues($keys)
    {
        $values = $this->useApcu ? apcu_fetch($keys) : apc_fetch($keys);
        return is_array($values) ? $values : [];
    }
protected function getValues($keys)
    {
        $values = $this->useApcu ? apcu_fetch($keys) : apc_fetch($keys);
        return is_array($values) ? $values : [];
    }
Retrieves multiple values from cache with the specified keys.
@param array $keys a list of keys identifying the cached values
@return array a list of cached values indexed by the keys