protected function buildDocumentFromArray(array $searchable)
    {
        $document = [];

        foreach ($searchable as $value) {
            $result = $this->$value;

            if ($result instanceof Collection) {
                $result = $result->toArray();
            } elseif ($result instanceof Carbon) {
                $result = $result->toDateTimeString();
            } else {
                $result = $this->$value;
            }

            $document[$value] = $result;
        }

        return $document;
    }