def make_optional(self, *args):
        """ Deprecated. will change in-place keys for given args
        or all keys if `*` in args.
        """
        deprecated('This method is deprecated. You can not change keys instances.')
        for key in self.keys:
            if key.name in args or '*' in args:
                key.make_optional()
        return self
Deprecated. will change in-place keys for given args
        or all keys if `*` in args.