RRule\RSet::offsetGet PHP Метод

    public function offsetGet($offset)
    {
        if (isset($this->cache[$offset])) {
            // found in cache
            return clone $this->cache[$offset];
        } elseif ($this->total !== null) {
            // cache complete and not found in cache
            return null;
        }
        // not in cache and cache not complete, we have to loop to find it
        $i = 0;
        foreach ($this as $occurrence) {
            if ($i == $offset) {
                return $occurrence;
            }
            $i++;
            if ($i > $offset) {
                break;
            }
        }
        return null;
    }