protected function _updateEnvVars(array $vars) {
        return f\reduce_assoc(
            function ($o, $var, $key) {
                // Store the current value
                $o[$key] = getenv($key);
                // Put the new value
                putenv("{$key}={$var}");
                return $o;
            },
            array(),
            $vars
        );
    }