src/Volume.php
private function _subfolder(): string
    {
        if ($this->subfolder && ($subfolder = rtrim(Craft::parseEnv($this->subfolder), '/')) !== '') {
            return $subfolder . '/';
        }
        return '';
    }
private function _subfolder(): string
    {
        if ($this->subfolder && ($subfolder = rtrim(Craft::parseEnv($this->subfolder), '/')) !== '') {
            return $subfolder . '/';
        }
        return '';
    }
private function _subfolder ( ) : string { if ( $ this -> subfolder && ( $ subfolder = rtrim ( Craft :: parseEnv ( $ this -> subfolder ) , '/' ) ) !== '' ) { return $ subfolder . '/' ; } return '' ; }
Returns the parsed subfolder path

@return string|null
Returns the parsed subfolder path