protected function getKeyArguments($arguments)
    {
        $keys = [];
        foreach ($arguments as $argument) {
            if (is_array($argument)) {
                $keys = array_merge($keys, $this->getKeyArguments($argument));
            }
            if (is_string($argument)) {
                $keys = array_merge($keys, $this->parseKeysString($argument));
            }
        }

        return $keys;
    }