public function getDateTimePickerOptions()
    {
        if (! isset($this->dateTimePickerOptions['language']))
            $this->dateTimePickerOptions['language'] = config('app.locale');

        $available = ['en', 'pl', 'sv', 'de'];
        $this->dateTimePickerOptions['language'] =
            in_array($this->dateTimePickerOptions['language'], $available)
                ? $this->dateTimePickerOptions['language'] : 'en';

        return $this->dateTimePickerOptions;
    }