code: func MSetsys(keys, values []string) error {
  	if !_IS_ROOT {
  		return ErrNoRoot
  	}
  	return _MSet(_SETTINGS.global, keys, values)
  }
docs: // MSetsys sets multiple values of the environment variables named by the keys
  // that affects the system as a whole. You must be Root.
  // It returns an error, if any.