Elgg\Cache\Pool\InMemory::get PHP Метод

    public function get($key, callable $callback = null, $default = null)
    {
        assert(is_string($key) || is_int($key));
        if (!array_key_exists($key, $this->values)) {
            if (!$callback) {
                return $default;
            }
            $this->values[$key] = call_user_func($callback);
        }
        return $this->values[$key];
    }