public function getCa() : ?string
    {
        if (isset($this->config['ca']) && is_file($this->config['ca'])) {
            return $this->config['ca'];
        }

        return null;
    }
public function getCa() : ?string
    {
        if (isset($this->config['ca']) && is_file($this->config['ca'])) {
            return $this->config['ca'];
        }

        return null;
    }
public function getCa ( ) : ? string { if ( isset ( $ this -> config [ 'ca' ] ) && is_file ( $ this -> config [ 'ca' ] ) ) { return $ this -> config [ 'ca' ] ; } return null ; }
Gets CA file from config.

@return string|null
Gets CA file from config .