src/DataLoader.php
protected function getCacheKeyFromKey($key)
    {
        $cacheKeyFn = $this->options->getCacheKeyFn();
        $cacheKey = $cacheKeyFn ? $cacheKeyFn($key) : $key;

        return $cacheKey;
    }
protected function getCacheKeyFromKey($key)
    {
        $cacheKeyFn = $this->options->getCacheKeyFn();
        $cacheKey = $cacheKeyFn ? $cacheKeyFn($key) : $key;

        return $cacheKey;
    }
@param $key

@return mixed