framework/caching/ApcCache.php
protected function addValues($data, $duration)
    {
        $result = $this->useApcu ? apcu_add($data, null, $duration) : apc_add($data, null, $duration);
        return is_array($result) ? array_keys($result) : [];
    }
protected function addValues($data, $duration)
    {
        $result = $this->useApcu ? apcu_add($data, null, $duration) : apc_add($data, null, $duration);
        return is_array($result) ? array_keys($result) : [];
    }
Adds multiple key-value pairs to cache.
@param array $data array where key corresponds to cache key while value is the value stored
@param int $duration the number of seconds in which the cached values will expire. 0 means never expire.
@return array array of failed keys