public function getFormatter()
    {
        if ($this->formatter === null && $this->config('formatter') !== null) {
            // Get formatter configuration
            $config = $this->config('formatters.' . $this->config('formatter'), []);

            // Get formatter class
            $class = Arr::pull($config, 'class');

            // Create formatter instance
            $this->formatter = new $class(array_filter($config));
        }

        return $this->formatter;
    }