protected function buildRadio()
    {
        if ($this->props['useFieldset']) {
            // 'auto' || true
            $this->props['template'] = \preg_replace('#^<div([^>]*)>(.+)</div>$#s', '<fieldset$1>$2</fieldset>', $this->props['template']);
            $this->props['template'] = \preg_replace('#<label([^>]*)>(.+)</label>#s', '<legend>$2</legend>', $this->props['template']);
        }
        $attribStrings = $this->buildAttribStrings($this->props);
        $props = \array_merge($this->props, $attribStrings);
        $props['input'] = $this->buildCheckboxRadioGroup();
        if ($this->props['tagOnly']) {
            return $this->props;
        } else {
            return Str::quickTemp($props['template'], $props);
        }
    }